Help Please quick question on electricity

[Sluicebox]

its still not clear to me why you need multiple relays though? i mean... just run all of the lights on the same circuit(flip 1) and simply switch the poles to the(flop 2) next ballasts.

Sorry but I'm failing to grasp this. Are you saying just come out of sub on 30 Amp circuit to 2 pole 2 throw contactor and flip the rooms that way? It would be way cheaper. I would still be able to wire a 120 Amp circuit for fans and such. If that's what your saying I dig it.

Would still be a 40 Amp sub, just running 4 lights at a time on a 30 Amp circuit. Could run this on 10 ga wire as well. So from 30 A breaker to 40 A tptt contactor ( I hope a bigger contactor is better here) then out to two sets of recepts 4 in each room.

24 volt coil on contactor, so mini volt timer runs it. Lights could be unplugged at recepts to remove from circuit.

Then pull 2x 120v 20A circuits one to ea room for fans and pumps.

If done this way is there room for 2 additional 120v 20A circuits to run A/C? 15000 btu, 12 Amp, 1370 Watts, 115V. One in each room? I know the units are under sized for 4 lights, but two hoods per room would be air cooled with outside air, the other two are just old school hoods.

Just didn't know if that original 40 Amp at the main service panel could handle all this load. I was planning on not using the a/c units and just going with passive air from outside with a 15 min off cycle every hour to run co2 burner. That is what I have done for the last 5 yrs with fairly good results.

I greatly value your input and look forward to your reply. Thanks again.

 

[Sluicebox]

As for the a/c circuit I could run that on one 20A 120v breaker and just flip the hot by adding a 3rd pole to contactor Then the a/c would flip much the same as the ballasts, and is only needed during lights on period. If this proves to be too much load for the original 40A breaker I could run only the a/c on the original room circuit as there would be nothing else on that circuit. Photo sensors power off my environmental controls anyway.

 

[Sluicebox]

So contactor would be 40 amp 240v 3 pole 2 throw with 10 ga wire from 30 amp breaker out of sub going to two of the poles and 12-2 hot wire going to 3rd pole. I know it's much higher ampacity but it is just a switch. 4x 10 ga hots on 240 come out 2 to each room, and 2x 12 ga hots come out one to each room for ac circuit. Neutrals from each circuit bypass the contactor as well as the grounds. All work done in proper box.

Does this work?

 

[Sluicebox]

I have been up all night trying to find this f'n contactor online, no dice. I went to HVAC supply house the other day and asked for a 40 amp 4 pole 2 throw contactor with 24v coil. Dude told me I was trippin, no contactor would be a double throw. I told him I'm no expert but I did watch a youtube vid last night on it and they do exist. It just has 4 normally open and 4 normally closed contacts. He said no way either you get a contactor with normally open contacts or an additional one with normally closed contacts, never find one in a double throw configuration. Swear to God I see them on youtube but can't find #s and yes they are a double throw. Witts f'n end here, please post a link to this thing so I can order it. You know exactly what I'm after, I do have a need for 4 poles on it. Help me find it and I will not bother you again. Best to all.

 

[Sluicebox]

2 of the poles would be for aux circuits, one for the a/c and the other for an inline fan on the lights. All would flip.

 

[Sluicebox]

Don't get me wrong please I'm not at all upset with anyone here. Just on 4th pot of rancid coffee and a screen full of dead end tabs. You guys are Rock Stars in my book. Thanks. Rykus, Queequeg???

 

[Sluicebox]

I think that I figured it out, will go back to HVAC supply today and look at that 4 pole unit again. I should be able to take a 4 pole normally open contactor and either apply power to flow through contactor either when the contacts are open or when they are closed. Add a jumper and it will work both ways.

 

[rives]

You have some terminology twisted up. Contactors are usually for motors or lights, and almost always have only NO contacts. In 30+ years of industrial work, I've seen a couple of contactors with NC full-amperage (not auxiliary) contacts for applications like multi-speed motors. They are very expensive and very rare.

Power relays commonly have NO/NC contacts. The following link is for an excellent source for this type of gear - http://www.automationdirect.com/adc/Shopping/Catalog/Relays_-z-_Timers/Electro-Mechanical_Relays/Power_Relays,_Open-Style,_40A_%28AD-PR40_Series%29/AD-PR40-2C-120A. There are many relays that have multiple NO/NC contacts, but most that are capable of handling heavy current are limited to single or double pole.

It looks like as the thread progressed you got onto the idea, but the breaker feeding the circuit needs to be rated for the same amperage or less than ANY downstream component - ie, no 15 or 20a receptacles on a 40a circuit.

Also, bear in mind that the 80% rule mandates that the circuit load for a continuous load (anything exceeding 3 hours) is limited to 80% of the breaker rating. So, a 30a breaker is limited to 24a of continuous load, or a 20a breaker is limited to 16a. Short-term loads can bump up to the full rating of the breaker.

Combining HID lighting and a/c on a heavily loaded circuit can create problems with the lighting dropping off line and re-starting when the a/c kicks on. Motors can pull several hundred percent current while accelerating - if they are on the same circuit as the lighting, the voltage drop during the inrush current can cause the lights to drop out because of HID's sensitivity to voltage sags.

"I should be able to take a 4 pole normally open contactor and either apply power to flow through contactor either when the contacts are open or when they are closed. Add a jumper and it will work both ways." - I'd be interested in seeing that circuit drawn out. I can't think of a way that a jumper is going to give you this ability.

 

[rykus]

IMO your getting off track now and confused a bit by terms, which as I am not an actual electrian could vary.... Here it is just in concept the 2 ways to do 2 rooms of 4000w off 40 amp breaker.

1. You have two complete ballast set ups. 40amp breaker - sub panel - 2 30a/240 breakers -2 on/off(contacter) each going to 4 recepticals powering ballast/lights in respective rooms. Uses 8 ballasts that could be unplugged, controlled by 2 timers and rest of panel is constant so fans ect still respond during lights out.uses zero "double throw"(relays) just 2 on/off(contacters) 1 for each set of 4 with its own timer to activate the power on/off to the ballasts of each room.this might be confusing, but it would almost be good to use a single relay to "flip" the power between the contacters, as it would prevent possibility of both sets of ballasts firing up.

2. This uses only 4 ballasts but requires "double throw"(relays). 40amp breaker- sub panel - 1 30a breaker- contacter(on/off set to 24hrs or switch)- ballasts(4) - relays (double throw electromagnet referenced earlier in pics,so lamp wire goes from r1-r2) controlled by timer set to 12/12 - both sets of lamps attach to relay r1 l1 l2 l3 l4 off one side r2 l1 l2 l3 l4 off other. If you connect the 3 commons together you can use 2 relays to flip 4 lamps.

Using 120v on same circuit any heavy draw items need to be balanced between both sides of 240v/40amp breaker. It is technically 40 amps per side, so if both AC where on 1 side they could potentially draw 24 amps on 1 side if both on plus the 20 amps the ballast is drawing on that pole = 44 amps on one side/20 on other. If both are on separate sides max draw is 32 amps per pole, and would be totally safe running 24/7 which would be way better for room conditions.

Try not to get lost in terms, think of the power as water and you need to use wires like ditches to get it to flow where needed... Anything is achievable, but really think of what would be best for you, your rooms, schedule ect. IMO AC and fans ect need to be on 24/7 for environmental control, but it's wet, cold, hot fluctuations all the time.

Main thing to remember is you need on/offs that can safely harness some high amps( which I refer to as contacter). And "flips" that can safely divert power between a single source- 2 draws(that I refer to as relay). That pic of the relay earlier in the thread is 100% what you want for high amps - 2 loads.

 

[queequeg152]

IMO you might need to slow down here. give yourself a week to figure all this out. seems like you are rushing here. it does not need to be built yesterday does it?

its still not clear to me why you need multiple relays though? i mean... just run all of the lights on the same circuit(flip 1) and simply switch the poles to the(flop 2) next ballasts.

Sorry but I'm failing to grasp this. Are you saying just come out of sub on 30 Amp circuit to 2 pole 2 throw contactor and flip the rooms that way? It would be way cheaper. I would still be able to wire a 120 Amp circuit for fans and such. If that's what your saying I dig it.

sorry, im not following 100% of the posts here. theres like 10 posts a day going on and i simply have not digested them all.

however, i think we are on the same page... just take power from your 40 amp sub panel, then into your box containing the dpdt contactor. from this box, you would take your cables to both rooms to power both sets of equipment.

a simple timer running on what ever power would control this contactor box.

however many lights you are runnign will dictate the size of this breaker.

regarding the sizes of your auxiliary circuits for fans etc.... if these are going to be 100% on all the time, then simply deduct the ampacity from the total.

you are probably not goign to be able to fit more than a 20amp double pole, and a 20 amp single pole.

you MIGHT be able to do a 20 amp double, and a pair of 15 amp singles... but not if you plan on loading them up to capacity.

i doubt you will be able to run ac systems ontop of all of the above... id suggest a 100 amp sub panel upgrade before you get into all of that.

 

[queequeg152]

I have been up all night trying to find this f'n contactor online, no dice. I went to HVAC supply house the other day and asked for a 40 amp 4 pole 2 throw contactor with 24v coil. Dude told me I was trippin, no contactor would be a double throw. I told him I'm no expert but I did watch a youtube vid last night on it and they do exist. It just has 4 normally open and 4 normally closed contacts. He said no way either you get a contactor with normally open contacts or an additional one with normally closed contacts, never find one in a double throw configuration. Swear to God I see them on youtube but can't find #s and yes they are a double throw. Witts f'n end here, please post a link to this thing so I can order it. You know exactly what I'm after, I do have a need for 4 poles on it. Help me find it and I will not bother you again. Best to all.

that guy must be new? most contactors may not be double throw... but LOTS are. double throws are invaluable for a shitload of reasons.

you asking for a 4 pole contactor is probably whats confusing him? a 4 pole contactor will not be a common item.

2 of the poles would be for aux circuits, one for the a/c and the other for an inline fan on the lights. All would flip.

id suggest running two contactors here... 1 dpdt(double pole double throw) and 1 spdt(single pole double throw) off of the same timer. it will cost less than a fancy contactor from grainger or where ever.

the double pole handles the 240 vac for the lights, the single pole handles the 120vac for the aux junk like fans and what ever.

you can also just get two dpdt contactors and just ignore the extra pole.

you simply run both contactor coils off of the same timer output circuit.

these coils draw like 50ma... nothing in terms of current. you could probably run 200 of them off 14 guage thhn wire.

again though... take some time to digest all of this.

i didnt learn all of this shit in like an evening on youtube. i dont think anybody can.
IMHO get some books of ebay like i did... best way imho. old literature is often better than new glossy shit books that cost 4x as much.

 

[rives]

Couple of things with rykus's comments -

1) If you use 30a breakers, then all of the downstream components must be rated for 30a - The wiring, receptacles, cordsets, etc. These are pretty expensive and unneeded. A more economical approach that gives excellent protection is to use a 40a circuit feeding the 40a power relay that I linked up above, and use that to feed a small sub-panel and then on to the ballasts. Small 4-8 circuit subs can be found for under $20. The ballasts can then be protected, individually or in pairs, with 15a breakers and you can use standard receptacles, etc.

2) If you use a flip, bear in mind that many electronic ballasts are not compatible with "hot flipping" where the power is left on and the relay just transitions from one lamp to the other. Many electronic ballasts have protective circuitry built into them that don't like this treatment, and it will void the warranty on some digitals. A "cold flip". where the power is turned off to the ballasts, the lamp relay makes it's transition, and the power is re-applied to the ballast will work with these ballasts, but it gets to be a pretty complicated control scheme. Magnetic ballasts are not impacted by hot flipping.

 

[queequeg152]

I think that I figured it out, will go back to HVAC supply today and look at that 4 pole unit again. I should be able to take a 4 pole normally open contactor and either apply power to flow through contactor either when the contacts are open or when they are closed. Add a jumper and it will work both ways.

can you link this 4 pole thing? im thinking you might be mistaking this thing for a regular dpdt.
almost all 3 phase hvac equipment runs on two conductors 208vac, the HUGE equipment and motors will run on three conductors.

im having a hard time imagining a time when an hvac install would require a 4 pole contactor? ive never seen such a thing outside of fancy equipment catalogs.

 

[rives]

can you link this 4 pole thing? im thinking you might be mistaking this thing for a regular dpdt.
almost all two phase hvac equipment runs on two conductors, the HUGE equipment and motors will run on three conductors.

im having a hard time imagining a time when an hvac install would require a 4 pole contactor? ive never seen such a thing outside of fancy equipment catalogs.

I've seen 4-pole contactors in size 0 & 1 used for 3-phase motor applications where the 4th contact was used for the holding circuit. Pretty old design, most have gone to using a small aux contact for the holding circuit. Motor contactors are going to be very expensive compared to power relays (several hundred dollars apiece vs $20).

 

[queequeg152]

I've seen 4-pole contactors in size 0 & 1 used for 3-phase motor applications where the 4th contact was used for the holding circuit. Pretty old design, most have gone to using a small aux contact for the holding circuit. Motor contactors are going to be very expensive compared to power relays (several hundred dollars apiece vs $20).

very interesting. ive never heard of that, but i know little of control schemes beyond super simple junk like hvac sequencing and interlocking and what ever else.

what do you mean by a holding circuit? same as a "stop and hold"? ive heard of those... though only as a reference to some latching relay scheme whereby a momentary button or switch is used to start some gigantic scary load.
guessing its not the same thing at all.

edit:
or maby it was a "start and hold"? idk, was on a waste water treatment plant motor control panel schematic that we got from a panel manufacturer.

 

[rives]

A holding circuit is used when the start button is a momentary contact rather than a maintained contact (like a toggle switch or ratcheting switch). The holding contact is wired in parallel with the start button so that power flow to the contactor coil is maintained when the button is released. It's probably the most common control circuit used for industrial motor control because it keeps the motor from restarting if the overload trips and is reset, like would happen with a maintained start button.

 

[Sluicebox]

Thank you so much everyone, sorry for being such high maintenance. I now have allot to think about. I did find a 4 pole 2 throw it is Square D LC1D258B7. Availability is 45 day back order. After reading all these wise replies I will just finish my run up to the sub and get first room going and take my time figuring out the flip. Will leave out the AC for now and go with passive fan intake.

I may have further questions for the smart bench, but will try not to blow up the thread with 10 plus posts per day lol.

You folks take care and thanks again. Rykus, Queequeg152, as well as rives, I do appreciate your input. I live in this house, I don't want to go off half cocked and get it wrong. You all have earned my deepest respect and gratitude.

 

[St. Phatty]

Thoughts? Thanks again.

BURN IN - just like in the electronics industry.

When you first set up the system, make sure you're there every second that it's on, for the first 24 hours to 3 days.

Also, feel the wires (through the insulation), to see how hot they're getting.

If it's anything more than slightly warm, I suggest getting a whatever-it-is with bigger capacity.

I have a melted timer that was run within spec.


Also - electrical contacts can build up crap. It's good to scrape them clean (or sand them), so that it's nice shiney metal on nice shiney metal (the electrical contact.)

 

[queequeg152]

thats an expensive unit.

check out the DPDT contactors.

http://www.amazon.com/RELAY-120VAC-30AMP-DPDT-HEAVY-FRAME/dp/B000JJM7ZS

never heard of that company though. you will probably pay more for a real brand like omron or square D or what ever.

 

[Sluicebox]

Queepueg, that's the same one from the youtube vid I was referring to. The guy was explaining how they worked, great vid https://www.youtube.com/watch?v=esmhpKOS-Sg I hope it's ok to post the link here. Also goes over how to read schematics dealing with relays.

I went to Lowes tonight and got everything but the contactors. Just wanted to let you guys know they have simmons service panels and cans on clearance. I got a bunch of them for $9 ea! Some were only 4/8 but got a few of the larger ones. Perfect for subs down the road. Pretty sure your local store will have the same deal as it's via corporate.