2+ Transformers on 1 Photocell ???

[GOTLIGHTS]

If there is anybody out there that knows how to connect three transformers together so that they can all be operated on one remote photocell, it would be much appreciated. This lighting system is massive (115+ lights) so I had to use 3 large transformers. Now my customer told me that he wants to have a photocell turn the system on at sunset, and a timer turn the system off at midnight. He never wants to worry about resetting timers when the power goes out, etc. We have a timer that will cut each transformer off respectively. The problem is the photocell. The three transformers are installed in the garage all in the same location. I do not want to use three separate photocells because I have to remotely mount them on the back side of his garage on the roof (this is only place that is in direct light most of the day because the area is extremely shaded). If I run three separate photocells, it would be a lot of wire, it would not look very good, and I still have the problem of each transformer cutting on at slightly different times. On this system I used (3) 1200 watt multi-tap transformers. I have located a photocell that is capable of handling this wattage.

On each transformer there are three taps where a photocell can be plugged in (common, hot, and the switch or interceptor).

There are three wires on the photocell as well which are the same. My question is how do I hook up this photocell so that it will control all three transformers? Please note that I do not want to intercept the main power line (30AMP breaker) that powers all three transformers. My guess is that I need some kind of relay system.... I really am stumped. If anybody has a solution please let me know.

[sitelights]

You can purchase a relay with the rating you require from McMaster-Carr (mcmaster.com) but you will not readily find a photocontrol to switch more than 2 kW.

It may be that you do not have a problem at all using multiple photocontrols. Consider that the switching threshhold for photocontrols of identical spec is probably a less than 1 footcandle spread. The likelihood of two identical photocontrols reliably switching at exactly the same light level is nil but they will be close enough for your purpose. Since you can mount three at the same location (using a 4" round J-box with a 3 hole cover) the aim and exposure will identical.

As you know, the photocontrol(s) will switch on well before it is entirely dark thus the perceived effect is not lights suddenly coming on in total darkness but rather that the lights will appear to brighten as the sky darkens. This is a kind of "soft" on that is not readily apparent unless your client intends to stand out there and wait to catch these three systems out of synch at dusk.

The "soft" on is the same effect as theater lighting that slowly ramps up at the end of a performance. What one would really like to achieve is a "soft" off or fade out (again like theater lighting) instead of sudden darkness.

The lights visually brightening as dusk progresses is aestheticly pleasing. The real problem is finding a method that would have the lights go out slowly. I have Lutron Grafik-Eye multi-channel pre-set dimming controls on all of my interior lighting and each of the master control locations allow dimming to out in from 1 to 60 seconds; a very nice effect.

I think your (and/or your client's) concerns are directed to the wrong end of the light show. It should be a simple matter to convince your client that the effect he desires is achievable at low cost using off-the-shelf technology. Our job includes guiding the client around these non-existent technical barriers.

If you can find a "soft" off device suitable for landscape lighting applications let me know immediately.

[K.L.L]

Sitelights, in a related post you made reference to setting multiple transformers as a "slave" to save on multiple control systems. Would this not be possible in the situation? If it is, how would one accomplish this? If it is not possible for this system, could you please explain in detail how to set a transformer as a slave ie: how many amp relay, wiring config, problems that may occur, limitations, and etc. If you feel artistically inclined, a schematic would be most helpful. Thank you in advance for all your help.

With kind Regards,
K.L.L

[K.L.L]

In reading into this further, it almost seems that it would be easier if each 1200w trans had it's own dedicated 10amp circuit. 3600w/120v=30amp, or each of three circuits @ 1200w/120v=10amp, then set the first trans with the controls and then use 2 relays to "slave" the other two transformers on the primary side. Primary transformer w/ controls ----> relay ---> "slave" trans w/o controls ---> relay ---> "slave" trans w/o controls (note: The relays cut the power between the breaker and the transformer). W/ the 30amp setup, I would run power to a seperate j-box with a relay between the two boxes. The relay would be a 120-12v. The trigger that Sightlights refers to in another post would come from the primary transformer, closing the relay and energizing the other two transformers. Just watch the amperage on the relay. Maybe Sightlights has an idea of how to "slave" on the secondary 12v side. Maybe he can elaborate on that for us. Not sure how that would work with the amp load that you will have. The only other thing that I can think of is if you use a control device on the Primary side, but you mentioned in your earlier post that you would prefer not to do that. Sounds like the Intermatic SS8 would do the trick as mentioned in another post b/c it is in a garage, out of the elements, and would not require a photo cell. The only problem would be finding a unit that would handle your required load. Sitelights is prob in his phone booth changing into his super hero costume, so he may come and save the day. Until then........

Regards,
K.L.L

[BRN]

What it sounds like to me is you need some contactors to control the secondary side of your transformers. The contactors will close when the photocell closes when it gets dark. You can also have the ability to have the contactors open with the timeclock as well, you mentioned having the lights turn off at midnight. The contactors require little power to operate so having 1 photocell is not a problem. The only problem I see with this is how many load side wires do you have coming off of the transformers?? If there are a lot then this option can get pricey.

Now I do have a couple of questions. You mention the taps on each of the transformers. What kind of power draw do they have?? If it is just control then usually they do not have a high demand. That being the case then you just run the wires down from your photocell (load and common) to your first transformer and then "daisy chain" wires to the other 2. The "Switch" connection sounds like a built in contactor which will take care of all the control for you. Just be careful not to go beyond the rating of your photocell when doing this.

[sitelights]

On the Product Review forum I posted "low voltage control devices" some time back. This post will tell you all I know about 12v/120v relays. Note that I am very reluctant to solve control problems by utilizing 120v circuitry. My goal is to avoid dealing with line voltage changes: I merely plug into an outdoor 120v receptacle rated at 15A and keep my load requirements well below that limitation.

I do not recall any posts where I suggest going internally beyond the outdoor receptacle and this is intentional: we never go inside.

Triggering three separate 1200w transformers can be accomplished in a myriad of ways but the three separate 15 amp circuits would have to be wired by a licensed electrician since it would require going to the panel. One could run the 120v photocontrol (load) to each of the transformers by simply breaking the hot within the transformer case without the necessity of going internally beyond the plug-in limitation. This is simply a remote placement of the photocontrol that would normally be mounted on the transformer case.

Elsewhere I characterize the simplest solution to a problem by using the word "elegance".

On the matter of secondary switching I have advised DIY members to avoid this because of the high amperage on the secondary circuits; lighting professionals are acutely aware of this limitation. A low voltage switch on a UL1838-limited 300w circuit would have to be rated for more than 30A and it would be foolhardy to use a normal 15A 120v wallbox switch for this purpose. In general it is safer and more cost-effective to switch the primary side in low voltage landscape lighting applications.

The more interesting (to me) aspect of the post relating to the control of three 1200w transformers was the notion of addressing the aesthetic problem and not the technical one.

[K.L.L]

Quote from Low Voltage Control Devices by Sitelights

"One or more 120v-12v relays activated by the 12v "trigger" of the main transformer output can switch a number of "slave" transformers on at the same time. These relays (one for each slave transformer) have the added advantage of reducing the switching load of the Grasslin Digi 42 wich is rated for 500w @120VAC. Grasslin's technical people state that their unit will handle a single 600w (2X300w) transformer and we buy our controlled transformers with the Digi 42 pre-installed. This relay method has additional applications such as the provision of outdoor 120v receptacles dedicated to temporary or holiday lighting: the lighting is switched on and off with the landscape lighting when plugged into a relay-controlled receptacle.

We use the 10 amp A-B (Allen-Bradley) catalog #700-HA32A12 and its base #700-HN100 or the 15 amp #700-HB32A12 with the #700-HN154 base. The plug-in relays look identical except that the 10 amp has a circle of 8 pins while the 15 amp has 8 tabs. The 15 amp base is dimensionally 3/4" longer than the 10 amp but each will fit into a 4" X 4" X 2" PVC J-box. If you have trouble locating the 10 amp unit go to McMaster-Carr* (mcmaster.com) where you can buy an exact clone of the 10 amp relay and base as their part #7170 K42 (relay) and part #7122 K11 (base) for less than $20.00 for both including shipping."
************************************************** ****

It should be quite clear that the information contained in these posts about working on the 120v side of the receptacle should be performed by a licensed electrician.
The above quote relates to working on the 120v side to install a relay-controlled receptacle. I assume you have your electrician do this kind of work when needed. In my opinion, installing the three photo controls would be the best choice, since it is not complicated and can be installed in a clean and professional manner.
Sitelights- Without working on the 120v side, in the past, how have you set transformers as "slaves"?

I have a senario for you.

*Transformer "A" is 50-100ft away from Transformer "B".
*You want to set Transformer "B" as the slave.
*How do you set Transformer "B" as the slave without touching the 120v side of the receptacle?

I think an answer to this senario will help many professionals in this industry. Pefect example of where this can be usefull is lighting both sides of a very large property. (not front and back). Added bonus: Save 1,2,3 or more pairs of transformer controls.

Sitelights- Thank you very much for your help and comments on this subject.

With kind regards,
K.L.L

[sitelights]

A transformer with a power cord and a control built into the case is a self-contained device. One plugs the transformer into a dedicated 120v unswitched 15A receptacle with a raintight-in-use cover. There is no need to change, adapt or reconfigure any existing house-mounted 120v wiring. The only concern is that the 15A rating of the receptacle/circuit is not exceeded; in fact, the load should be at least 20% less than the maximum rating i.e. 12A.

Controlled transformers have built in devices to interrupt the flow of 120v current to the windings of the transformer thus turning the transfomer on and off. These internal control devices include primary thermal overload bi-metal switches imbedded in the potting of the core(s), magnetic circuit breakers to protect the secondary output from short circuits or polarity errors, a timer that automates the on-off cycles of the lighting and, in many cases, a photocontrol to detect dusk is in line with a timer to turn off the photocontrol at a pre-set time.

The point of connection to the 120v circuit is at the plug end of the transformer power cord; no other point of contact with the 120v feed from the house circuits is needed. All of the 120v current control within the transformer is via the above listed control devices. These devices all operate on the same principal: they break the connection between the incoming 120v current and the power supply. The 120v circuit to which the tranformer is connected can be positively disconnected from the 120v current. This is a form of "air-gap" switching in that there is no physical or mechanical connection to the primary power supply. Unplug the transformer and what you have is a rather expensive boat anchor.

An internal 12v/120v relay merely augments the internal devices that switch the transformer on and off when it is plugged in. The hot side of the 120v supply within the transformer is interrupted by an air-gap switch within the relay. The switch within the relay is normally open; it is closed by 12v current from a "master" controlled transformer. When the "master" is on the "slave" is on and vice versa. Each "slave" and "master" transformer is plugged into outdoor receptacles at different locations. If the "slave" and the "master" are side-by-side it is much simpler to put the "slave" in series with the "master" (only the "master" is plugged into the house current since the "slave" is connected to the "master") by a direct connection between them but one must be careful to stay within the 15A rating.

A closer reading of the referenced post will show that I do not refer to controlling a 120v receptacle with a relay but rather putting a separate outdoor receptacle in close proximity to a controlled transfomer and powering the receptacle (holiday lighting) from the transformer so that the additional temporary lighting switches on and off with the landscape lighting.

None of the switching or controlling occurs other than within the transformer case (or in an R3 enclosure if the relay is outboard). It is not required to have an electrician's license to plug a device into an existing outdoor receptacle. NEC requires that there be a way to positively disconnect a device from the 120v feed; this is why I discourage hardwiring transformers.

I do not agree with your statement concerning the necessity of having a licensed electrician install a self-contained plug-in device. If this were true one would need an electrician standing by in case one would want to use an outdoor receptacle for any purpose.

To make myself perfectly clear on this point it is necessary that you understand that a plug-in device is downstream from the outdoor receptacle and is in no way permanently attached to the 120v supply. The relay merely takes the place of a timer or photocontrol by acting as a 12v triggered switch to turn the transformer on and off. The 120v current is not switched before or at the receptacle by the relay; it is switched outboard and interrupts only the hot feed coming through the plug-in power cord.

In a number of my posts I have alluded to the fact that we occasionally call in a licensed electrician to provide us with outdoor receptacles if none exist. We have infrequently installed a single outdoor receptacle ourselves using the NEC-mandated GFCI receptacle mounted next to the main interior electrical panel as our connection point. These GFCI panel receptacles are dedicated circuits and thus have no load other than what is plugged into them. One should never use a GFCI panel receptacle as a source of power for an outdoor outlet if there is a refrigerator or a sump pump or some other critical piece of equipment plugged into that receptacle.

[K.L.L]

I was unclear in your post when you had mentioned,

Quote from Low Voltage Control Devices by Sitelights
"This relay method has additional applications such as the provision of outdoor 120v receptacles dedicated to temporary or holiday lighting: the lighting is switched on and off with the landscape lighting when plugged into a relay-controlled receptacle."

The use of "relay-controlled receptacle" led me to believe that you were speaking of installing a relay between the breaker and the receptacle.

Quote from "Slave"? by Sitelights
"To make myself perfectly clear on this point it is necessary that you understand that a plug-in device is downstream from the outdoor receptacle and is in no way permanently attached to the 120v supply. The relay merely takes the place of a timer or photocontrol by acting as a 12v triggered switch to turn the transformer on and off. The 120v current is not switched before or at the receptacle by the relay; it is switched outboard and interrupts only the hot feed coming through the plug-in power cord."

Thank you for clarifying that for me.

Quote from "Slave"? by Sitelights
"I do not agree with your statement concerning the necessity of having a licensed electrician install a self-contained plug-in device. If this were true one would need an electrician standing by in case one would want to use an outdoor receptacle for any purpose."

That was not the meaning of my statement. This stems from the miscommunication of terms from the above posts.
I believe we are clear about the above mentioned information.

Sitelights- Thank you for taking the time to clarify this information for me. I had been a visitor on the site for many months and have made the Search Function my best friend (see my profile). This is the topic which pulled me into the mix, and I thank your for your thorough explanation.

With kind Regards,
K.L.L.

[sitelights]

I avoid switching the secondaries because (1) The amperes are X10 on the secondary vs. the primary; a 300w load at 120v is 2.5A but at 12v it is 25.0A. At higher amps there is an increased incidence of arcing if the connections are not rock solid. (2) Switching the primary side of the transformer turns it completely off; switching secondaries leaves the transformer operating continuously. This results in the transformer operating with zero load for the entire time that the secondaries are switched off by the contactor. A low voltage lighting transformer should not be operated with no load. (3) Low voltage rated dimmers and/or standard photocontrols are made to switch the primary only. (4) Using all the taps on a com-com-12v-13v-14v-15v multitap 300w transformer could result in as many as 24 low voltage conductors to the transformer. Even if only half the conductors (the commons for example) were switched 12 contactors would be needed. Imagine if there were 4X300w in the same case.

I think the three photocontrols with 1200w on each approaches or matches their design maximum rating which is normally from 1200w to 1600w incandescent for off-the-shelf items.

I am not clear on the question of "power draw" on the multitap outputs. It is possible to use all of the taps as long as the total lamp load does not exceed UL1838's 300w per core. The "power draw" on each tap would vary with the system design since the lamp (and cable) loads would be different on each tap. Have I answered the question?

[GOTLIGHTS]

SITELITES....
After reading through all the responses, I think that my best option is to have one of the transformers set up as a primary, and the other two set up as "slaves". As you mentioned before, my main concern is that this system operate flawlessly, and look like it was professionally installed. My customer obviously spent a lot of money on this system, and the last thing I want is three power lines run up the back side of his garage for remote photocells. I think i can easily hide the wire for one remote photocell and then have the other two operate as slaves.

Would it be possible for you to post a picture of how to wire up the relays, etc involved in setting up a primary-slave-slave system? I would greatly appreciate it. If you cant, I will call an electrician and have him wire up the transformers in this manner.

Thanks alot...

[sitelights]

My suggestion in favor of three photocontrols was driven by a consideration beyond the points of discussion. You have a 30A load (3 X 1200 = 3600/120 = 30) on a 30A breaker which amounts to zero "headroom". The full 30A load (two relays plus the main transformer) would switch on simultaneously and the breaker would be expected to handle that load as "in-rush" current. This subjects the breaker to its maximum rated capacity as a single surge.

I would be inclined to drive the three 1200w transformers via three 15A circuits. The in-rush current would be 66.666(endless sixes) per cent of the rated capacity of the 15A breakers rather than the 100% load on a single 30A circuit. You can operate a 30A breaker at its full rated capacity but a change in the input voltage from the power company, which may range from 110v to 130v over the course of a year, would place a load of up to 33A at 110v. This is asking for trouble.

My suggestion was based on sequential rather than simultaneous application of the load. An electric motor may initially draw current in excess of breaker capacity and then drop to the normal operating load (the rationale for slo-blo fuses). A transformer load of 3 X 1200w is a steady-state demand. The total lamp load is more than likely less than the 300w rating per core. A load of 200w per core would yield a total load of 800w X 3 = 2400w or 24A. The problem lies in the ability of the 1200w units to handle 1200w; the theoretical maximum capacity is the operant factor thus there is no "head room" in your design using the worst-case scenario.

Also note that the relays described in another post are rated at 10A; a 1200w transformer can draw as much as 11A at 110v input. Just as I design for a 75-80% load on a transformer (head-room again) one should also design for something under (i.e.75-80%) the theoretical 100% operating load.

There are 15A relays available (A-B 700-HB32A12 relay; A-B 700-HN154 base) but the potential trouble lies in the 30A bottleneck. I would not do what you propose. You should explain the design to a licensed electrician (since this is not a 12v problem) so that a code-compliant, NEC-approved solution can be put in place. I could provide you with images, diagrams etc. for the wiring of these relays but my inner attorney prevents me.

Your need for a bullet-proof, reliable control system for these monster 1200w transformers* (we never use more than 2 X 300 units) requires a sound, well considered, expertly prepared solution. My curiosity compels me to ask what type of battery back-up, DST compensation timing device you intend to use to turn the photocontrol(s) on and off.

*These cumbersome (they must weigh close to 50 lb) multi-core transfomers make no sense to me at all. The design parameters of the system were apparently supplied by your client. A much more flexible system with multiple 2 X 300w units distributed strategicly is more to my taste. A large system (over 100 fixtures) that relies on every main cable beginning at the same point is, in my opinion, fatally flawed from the outset. My guess is that you are using the high volt (12-22v) concept to hit these fixtures with target voltage; there must be quite a bundle of cables leaving that garage. The multi-core concept reminds me of these all-in-one (fax, printer, scanner, copier) computer peripherals where one fails and the entire unit is junk. At an average of about $.80 per watt for a 300, 600, 900 or 1200 there seems to be no price advantage; in fact, quite the contrary all things cosidered.

[GOTLIGHTS]

In response to some of your comments... Yes there are 3 1200 watt transformers plugged into one 30Amp circuit. However, there are only approximately 900-950 watts on each transformer. I have an amperage clamp meter that I have looped around all three of the power cords and that maximum amperages that I have read is 22Amps. So I do not think that I am overloading the circuit. Then I tested each transformer individually, and again found the same results of less than 22Amps. I always do this to insure that I am not overloading a circuit. In my opinion it is the only way to make sure that you have properly conntected the system. I go as far as testing every wire coming out of the transformer on the secondary side as well. If there is a bad connection, bad bulb, etc. the system may pull more amps than it is theoretically supposed to. So I do no think that I am overloading the circuit at all.

Also, on the secondary side, some of the lines are hooked up to the 15V output. These lines actually pull less amps from the transformer than they would if they were hooked up to the 14V, 13V, or 12V tap.

On a transformer of this magnitude I would never use any relay less than 15Amps, it simply would not be logical.

I agree that these three 1200 watt transformers are massive and difficult to mount. However, it seems illogical to me use 6 600 watt transformers scattered around various locations. The man I installed the system for wants something that is easy to control, easy to check on, and basically trouble free. If I had 6 transformers scattered around his home, that would not be professional. So lets say a breaker trips in a transformer, he would have to go on a wild goose chase to find which breaker tripped and where it is! Now all he has to do is go in his garage and check all thre breakers in one location. (This is not say that I think the breakers will trip-- I wired the system in a manner in which I think they will never trip unless a line is cut)

And yes they are heavy, but they were not hard to mount at all. Then two pounds or fifty pounds, it doesnt matter because they are on a wall.

And now to contradict some of what I have just written. This man already had a system in place. Due to the fact the has a $100,000.00 irrigation system, and hundreds of thousands of dollars in rare and exotic plants, I made the executive decision to reuse a lot the existing wire which was mainly 8/2 and less than 5 years old. The last thing I wanted to do is tear his garden up burying new lines.

I guess what I am trying to say is that I feel that I have installed this system by the text book. Nothing is overloaded, everything is clean and neat, and it all works flawlessly. All I want to know is how to wire up the relays. If your "INNER ATTORNEY" feels like should not help me and the others who have been following this thread, then I guess we will all have to look else where for the answer. TO all the others out there, if Sitelites will not help us, I will post the answer to this question when a licensed electrician comes to wire up the relays for me.

One more thing, where did you get the figure of 80 cents per watt? I think it should be more like 25 cents per watt when you purchase a transformer. Did you mean that you resell the transformers to your customers at 80 cents per watt?

I am not trying to offend you. I just want you to know that this system has been installed to perfection. I simply would like to know how to wire in these relays. Thanks Alot.

[sitelights]

The wiring diagrams are printed on the relays.

The $0.80 per watt average for transformers was the average list price of a bare (no timer; no photocontrol) stainless steel case transformer divided by the rating. I arrived at this figure by using the MRSP listed in the catalogs of: Unique, Vista, Hadco and Cast which fell readily to hand.

At your figure of $0.25 per watt the 1200w transformer would cost $300.00 If you can purchase a 1200w s.s. multitap transformer with magnetic breakers at this price you are sourcing from the Non-Profit Transformer Company.

I caution you to not lowball your prices to your clients or to non-professional DIY guests and members on this site. These unrealisticly low prices mislead the public. By definition a low voltage lighting professional works for money; it is a disservice to customers or, my preferred designation, clients to not to make a profit on your work. If you cannot make a profit, you cannot stay in business to service what you install; what you have without profit is not a business but merely a job.

Nationwide the average installed retail price of a professionally designed and installed low voltage outdoor lighting system is about $200.00 per fixture when handed over to the client.

There is a mention of the client being in the maintenance loop (breakers, etc) and this is not what clients want. By presenting a client with another system to maintain you work against the self-interest of the owner and the provider. We are in a service business; we are not selling hardware and sweat, we are providing aestheticly pleasing, expertly installed, no-maintenance lighting effects to enhance the property and grounds of our clients.

I, personally, find the technical aspects of system engineering and installation rather boring. I confess to being a show horse not a work horse. My interest is in what is new and what is challenging and my focus is on the work as a vehicle to make real my lighting design ideas and concepts. Lowvolt.org provides the opportunity for me to fully disclose everything that I have learned (the hard way) and pass along this information to others of similar interests. I do not claim infallibility; I am not the Pope. Elsewhere on this site a member wrote something to the effect that you can't learn unless there is a difference of opinion and I concur with that idea.

I am only rude intentionally but my candor may at times may be objectionable; this is not a personal matter, simply an aspect of my zeal.

[Eden Lights]

Always surround yourself with best people available and you are destined for greatness. Hire an experienced controls electrician and he or she will be worth every penny. Most of the guys and girls will really want to help you because in most major locales this type of work starts at around 15K so they are apt to teach you instead of taking this level of job. In the last couple of months I have been studying and playing with some automation on a transformer using the new UPB controls and a couple of the local guys have been great in getting me going. Our clients want more and more controls regardless of what we think they really need. Good luck.

[BRN]

Well. . . I am a licensed electrician. Most of what SiteLights has said I agree with completely. His cautiousness for just giving an explaination comes with experience. Please don't frown on him for that.

Like he did state though the transformers should have a diagram explaining how to terminate each point in it. Check there first. If you cannot find the schematics there than what you will want to do is wire the control side of the transformers in a series configuration.

The easiest way for me to describe this without a picture or actually being there would be like this. Connect term point "common" from the master transformer with term point "common" on both the slaves. The same would go for term point "switched". You should not have to terminate any of the slaves to the "hot" as that is what provides power to your photocell. You only have to do that once.

***First thing you want to do is check for a wiring diagram/schematics that should be with the transformers!!!! If you cannot find one with the transformers then check the web for the model transformers that you have, you can find anything on the net ;)

[LowVoltPro]

EASY GUYS!! Unique lighting makes a device called the Sequencer. It is a plug in module that essentailly works as a relay. What you do is take your first TF with timer/photo cell and simply run a small cable from the 12v tap of that unit to the next TF with the sequencer plugged in place of where the timer normally goes. You wire one half of the cable to the red knob the other half to the black. From there you run another cable from the 2nd unit now a slave off of the same red and black knobs to the 3rd unit also now a slave and repeat the step. Simple easy and it works every time. You can also utilize the sequencer with UPB timing systems, X10 and whatever other system you want.

[Tesla]

Sequencer is a cheap and fast way to go, all explained above. Not always fast, I've had transformers that sequencer won't fit in, so I remove those plastic knobs, cut down metal pieces and put wires there and protect with tape, not professional, but works. I'm confused with 30AMP circuit. I've installed 4+ TF systems, and we do 3 or 4 dedicated circuits, each 20AMP. We sequencer them regardles of their position (sometimes outlets are grouped in one place, sometimes are all over property), other times we relay primary outlet with 30AMP 12VOLT relays. One of the transformers is master with photo eye and timer, then you take low volt "signal" from master and energize relays on primaries for the rest of transformers.