One switch controls all the light circuits

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Swapping out to something quiter will be cheaper than relocating everything. Unless you suspend the control box with an elaborate mounting system, you will still have hum.


No, I just thought all along that the contacts where just old and tired...
 
Well, I figured the job to take about an hour, maybe an hour and a half depending on how quick we can penetrate the brick to install the 6" piece of PVC from the inside panel to the outside JB. From there it is just moving the contactors, routing some THHN, making joints and landing wires. I figured 4 hrs (maybe 3) total considering the 1.5 hr + round trip drive (depending on traffic). Trust me I will look into these alternatives that I have never run across before. Knowing my boss though, he wont wait for my research, he just wants work to keep us busy.

Well, if busy is what you want to be, then you can certainly relocate the whole shebang. If you're locating the box outside, you'll also need a 3R box as well.
But I'm sure the customer would be more than happy with the ice cubes since there's a whole lot less labor involved. :cool:
 
Ice cube relays are for pilot duty, I would not recommend using them to directly control lighting circuits.

Go with mechanical held contactors, or just move the existing ones as the customer wants.
 
yea dude, just move them like they want you to. You already practically made the sale, so whats the deal? Charge them for 4 homeruns and to rewire the contactors..and move on with it....!
 
Yes, go head and do what they want, since you charge them for it. I have seen people want 'contactors' for their stove on a timer. Why? they didnt want their parents/kids to forget and leave the stove on. Just give them what they want.

I actually had a place that had the bathfan put on a timer and light switch to make the fan come on whenever they are in their by using the 'ice cube' relay. Mind you the amp draw is substanstially lower (1 amp at most) than the lights u may have and it runs no more than 45 minutes at a time.
 
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There is a trick to extending the life of contacts used near their ratings: place them in series (yes, series, not parallel.)
 
Ice cube relays would work just fine for a simple lighting load just use quality relays like a potter brumfeld quality.The issue that everyone is avoiding is that the contactors shouldnt hum unless there is a problem with them. Magnetism is an inverse square of distance so a small rusted coil will cause chatter on a relay. Clean the coil closure of all light rust and protect it from a wet environment and the humm goes away. LIght sandpaper and a little mechanical skills to dissasemble and you are in like flynn.
 
Or use a contactor with a DC coil. A simple bridge rectifier and capacitor can make some useful DC power for operation of a contactor. You can make a 24 Volt DC power supply using a 16 V doorbell transformer, and a bridge + capacitor for less than $25. :grin:
 
There is a trick to extending the life of contacts used near their ratings: place them in series (yes, series, not parallel.)

OR you can just use a relay with the correct rating to start with.


Ice cube relays would work just fine for a simple lighting load just use quality relays like a potter brumfeld quality.

Whatever you want to believe.

I work with this stuff all the time and have replaced many melted or welded ice cubes. They are good for many things, direct control of a 15 or 20 amp circuits is not one of them.
 
you could use solid state relays, no noise, and no melted ice cube relays. Make sure you over rate them 100% (use a 40amp relay) these need low voltage DC to control them, so place a little 5vdc power supply between them and the switched 120v. Mount them to a metal can with a good amount of surface area and use heatsink grease under them. Cost you around $25ea plus a few bucks for a little power supply. You need the type that say 'Zero Crossing'
 
I forgot to mention, the ice cube relays will burn up pretty quickly due to the inrush current from a bunch of lamp filaments. For example, I am looking at a mechanical relay with a general purpose contact rating of 40amps @ 277v, but the rating is only 10a @ 120v when the load is tungsten lighting.

And with the solid state relays I mentioned, if the only load is a couple CFLs, they lamps will randomly flicker when off due to leakage current charging the cap in the ballast.
 
Ice cube relays are for pilot duty, I would not recommend using them to directly control lighting circuits.

Go with mechanical held contactors, or just move the existing ones as the customer wants.

What's the advantage of mechanically held vs electrically? Why would you use one over the other?
 
What's the advantage of mechanically held vs electrically? Why would you use one over the other?

general purpose contactors are inexpensive, but they require a magnetic coil to be energized to hold the contact closed, and they tend to hum and chatter especially after they get a little age on them. Mechanically held contactors only need a momentary contact switch to engage the solenoid and like the name says, they are held in place mechnically "no electricity needed to hold contacts closed" but they will need another seperate switch leg to make the contactor open, so you would need either two momentary contact buttons, or a single pole double throw switch to operate it (you could use a three way switch). the main advantage for a mechanically held contactor in this case is they dont chatter or hum, another disadvantage is they cost quite a bit more....
 
general purpose contactors are inexpensive, but they require a magnetic coil to be energized to hold the contact closed, and they tend to hum and chatter especially after they get a little age on them. Mechanically held contactors only need a momentary contact switch to engage the solenoid and like the name says, they are held in place mechnically "no electricity needed to hold contacts closed" but they will need another seperate switch leg to make the contactor open, so you would need either two momentary contact buttons, or a single pole double throw switch to operate it (you could use a three way switch). the main advantage for a mechanically held contactor in this case is they dont chatter or hum, another disadvantage is they cost quite a bit more....

Good explanation. Thanks.
 
Cutler Hammer makes an inexpensive 3pole contactor that I have used to switch landscape lights when my ding dong helper trenched in a 2 wire for the 3 way switches.
 
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