Timeclock wiring

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JAMAN

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A project i'm currently working on, the owner would like the parking lot lighting to be controlled via timeclocks. The fixture heads are 208v and the business has winter and summer operating hours. The owner would like a timeclock where it can be set once and never have to be readjusted despite the 2 different operating hours.

I spoke to a timeclock manufacturer and the tech guy recommened an electronic timeclock with SPDT contacts. I informed him that the fixtures were 208V L-L and that SPDT contact would only open one of the legs and not both. He said that this is OK and done all the time.

Have any of you wired fixtures this way? And is this even allowed by code? I've searched through article 404 but doesn't mention about timeclocks having to disconnect all ungrounded conductors.

Thanks for the help.
 
You will need to open both legs of the 208 volt circuit.
How about a double pole timeclock or let the timeclock control a 2 pole contactor
 
I forgot to mention that the parking lot lighting consists of 4 circuits. The timeclock recommended by the tech guy is a 4 circuit SPDT. This setup is ideal becuase it would only require 1 timeclock. I can not find a manufacturer that makes a 4 circuit DPDT timeclock.
 
raider1 said:
I would recommend using a lighting contactor that would be controlled by the time clock.

Chris
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Agreed, that's been the standard practice for places I have worked. Use a Square D Class 8903 LC (LG-40 for 4 pole) and hook it into your timeclock like Chris said.
 
I also agree a contactor is a good way to go.

But I also thought Intermatic had a time clock with 8 contacts.

Steve
 
I was referring to having to open both hot legs in the light fixture. The original poster made reference to only opening one leg in the fixture which would leave one leg hot in the light even though it is not lit. Safety issue

Like I originally posted - let the time clock control a contactor and break all hot legs going to the fixtures
 
Go with a PROFILE timeclock. They have no interface on the timeclock itself, everything is satelite controlled. They have 4 relays, for 4 different settings. Time is always accurate (controlled by satellite). All of the settings are set up via internet.

Sorry, dont have a link
 
Great idea, never thought of using contactors.

Since I have 4-2pole cb's powering all the lights, I would need an 8pole contactor.

I looked through SquareD's catalog and they have electrically and mechanically held contactors. What are the advantages to either one? The catalog doesn't mention what the coil draws for current. Any idea?
 
Although 410.81 says that luminaires whose secondary voltage is 1000v or greater should have all ungrounded conductors disconnected for control purposes, I see no other article which requires a luminaire of 1000v or less to have that requirement. Could one of you point me to that article (since you seem to have indicated that NEC requires that ?)

FWIW, it is standard practice to disconnect all ungrounded conductors, but I was not aware that it is required for luminaires for switching purposes.
 
in my limited experience, mechanically held is NOT what you want for timeclocks or photocells. also the coils ive seen for small contactors like that draw almost Nothing.
 
ok I guess 410.54 B requires all the ungrounded conductors to be switched at the same time if the device is auxilliary equipment (contactor), but does 410.48 apply to HID ?
 
izak said:
in my limited experience, mechanically held is NOT what you want for timeclocks or photocells. also the coils ive seen for small contactors like that draw almost Nothing.
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They can be used with an ice cube relay or a RIB relay, just has to be double throw for the latch and unlatch coils, electrically held though is a heck of a lot cheaper. Though a lot of digital time clocks now have an astronomical function to adjust for sunrise and sunset, a photocell can also be used to automatically adjust for seasonal changes. Wire for photocell on, time clock off. Saves a lot of energy while keeping the parking lot properly lit.
 
ok please learn me here I always thought 208v was on a stinger leg Y style with the middle point going to ground . Why or how do you get 208 on two legs wouldnt that be 240v? Thanks in advance
 
billdozier said:
ok please learn me here I always thought 208v was on a stinger leg Y style with the middle point going to ground . Why or how do you get 208 on two legs wouldnt that be 240v? Thanks in advance
Click to expand...

C'est very simple the 208 volts is devired from 208Y120 volt system the Y letter is wye due the center is netrual and line to netural is the same all phases and you read line to line on wye is 208 on this example.

This can be treated as single or triphase depending on the phase conductors you used.

The 240 volt it will go either Delta { there are few verison of it } and some area used 240 v Wye { very rare in usa } and yes you can get both in single or triphase verison.

Merci,Marc
 
billdozier said:
ok please learn me here I always thought 208v was on a stinger leg Y style with the middle point going to ground . Why or how do you get 208 on two legs wouldnt that be 240v? Thanks in advance
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Bill, you're one of the few here who are more familiar with high-leg Deltas than 208/120v Y systems. The high-leg Delta (esp. open-Delta) began as a 3ph modification to existing 120/240 1ph services.

A high-leg Delta, as you know, is a Delta which has the center tap of one secondary bonded, which is what creates the (unuseable) 208v to ground on the high leg, and can be either an open or closed Delta.

A Y system is one with three 120v secondaries, with the "same" end of each tied together, and that junction, which is the neutral, bonded. That gives you three hot wires, each of which has 120v to ground.

Because the three hot wires have their peaks 120 degrees apart, instead of the 180 degrees one usually thinks of (from the neutral's point of view), the hot-to-hot voltage is 208, not 240.

Now, unlike the 208v you're familiar with, the line-to-line 208v is quite useful. You can supply 120v 1ph, 120/208 3-wire, 208 3ph with or without neutral, etc.

Just about nobody would spec a high-leg Delta for an all-new installation.

By the way, my choice for contactors would be either two 4p or four 2p relays, the former of which you can get from Grainger for about $45 each in 20a rating, and just parallel the coils for operation from any 120v 1p timer.

Be sure to wire each 2p circuit to pairs of contacts of the same relay; in case one fails, you'll lose half of the lights instead of all of them.
 
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Larry thanks for clearing that up for me. Yeah we dont ust the 120/208 delta configuration much but I had a kickass jman who tried to teach an eager helper all about deltas and ys for whatever reason the stinger part stuck with me more than the others probaly cause the emphasis was on not hooking any 120v circuits on that wire keep the smoke in
 
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