Snow melt tapped from AC disconnect?

[Wyatt Earp]

Here is the situation, I have a job where the electrician tapped off the 30 amp AC disconnect into a 2 circuit outdoor panel and installed a GFCI 2 pole 20 amp breaker for some 240 volt 20 amp snow melt cable which is controlled by a thermostat that shuts it off if the temp is above 40 degrees. Would this installation be code compliant since the thermostat would prevent the snow melt and the AC from coming on at the same time. Any help would be appreciated.

 

[Sierrasparky]

More information would be needed.
How does the ice melt Ithermostat regulate the A/c compressor?

 

[stickboy1375]

More information would be needed.
How does the ice melt Ithermostat regulate the A/c compressor?

It doesn't... but what he is saying is that, the AC won't be running at the same time as the Snow Melt.... For what its worth, I don't see an issue with the current setup...

 

[Ponchik]

IMO. it sounds like he using the existing A/C circuit as a feeder as well.

He has to turn the A/C circuit into a feeder and feed the outdoor subpanel, then install a new A/C circuit from that panel and the circuit that you are using for the deicing equipment.

 

[stickboy1375]

IMO. it sounds like he using the existing A/C circuit as a feeder as well.

He has to turn the A/C circuit into a feeder and feed the outdoor subpanel, then install a new A/C circuit from that panel and the circuit that you are using for the deicing equipment.

That was my take on it, not sure if that's what actually took place or not.

 

[hurk27]

IMO. it sounds like he using the existing A/C circuit as a feeder as well.

He has to turn the A/C circuit into a feeder and feed the outdoor subpanel, then install a new A/C circuit from that panel and the circuit that you are using for the deicing equipment.

I think you mis read the OP, it says the electrician tapped a 2 circuit panel off the A/C disconnect, and installed a two pole GFCI breaker, he could not have moved the A/C to a breaker in this new panel and used a two pole GFCI, and it doesn't say he did.

I don't see a safety problem with it if all other codes are met? about the only one I could see is putting two wires under a terminal listed for only one wire.

 

[Chamuit]

I think you mis read the OP, it says the electrician tapped a 2 circuit panel off the A/C disconnect, and installed a two pole GFCI breaker, he could not have moved the A/C to a breaker in this new panel and used a two pole GFCI, and it doesn't say he did.

I don't see a safety problem with it if all other codes are met? about the only one I could see is putting two wires under a terminal listed for only one wire.

I saw this exact setup today at a job. The piggy-backed circuit was for a 240V mist system.

 

[Sierrasparky]

it sounds like it will work but I don't see how it is code compliant. For one the load on the A/c circuit may be exceeded.
How was the tap made. Two wires under a single lug. What is the wire capacity of the disco? Sounds to me like more info necessary to make a call to say ok!

 

[kwired]

There was a similar debate a while back about taping off an electric clothes dryer circuit to supply some minimal load (can't recall what it was)

Most people seemed to agree on the fact that you would need to make the existing branch circuit into a feeder then put a breaker for the dryer and another breaker for what ever the other load was.

I know of a few commercial places that do run A/C even in cold weather so you may want to make certain they will not both operate at same time. Probably unlikely in dwellings. If it is a heat pump .... they usually draw less current the colder it is outside, but even if it ok to connect both to the same feed, is it enough less, and will it still handle starting current with additional load on the circuit?

 

[hurk27]

it sounds like it will work but I don't see how it is code compliant. For one the load on the A/c circuit may be exceeded.
How was the tap made. Two wires under a single lug. What is the wire capacity of the disco? Sounds to me like more info necessary to make a call to say ok!

I agree it seem like it should be, but I can't find anything

As far as over loading the A/C circuit the OP stated that the snow melt circuit is protected by a 2-pole 20 amp breaker, and the fact they both would not run at the same time, and if they did ever accidentally kick the air on, what would be the most that would happen? breaker trip?

 

[Sierrasparky]

I agree it seem like it should be, but I can't find anything

As far as over loading the A/C circuit the OP stated that the snow melt circuit is protected by a 2-pole 20 amp breaker, and the fact they both would not run at the same time, and if they did ever accidentally kick the air on, what would be the most that would happen? breaker trip?

Don't you need to rate the circuit properly?

Does the A/c and the Ice melt combined loads correclty calculate on a 30 amp circuit?
Does the A/C disco allow for the tap?
What prevents both being on at the same time? User does not count must have some sort of interlock!
Is the ice melt protected by a EPD type GFCI or similar?

This install is not code compliant but may work.

 

[Wyatt Earp]

May be a little more info would help. The AC (not a heat pump) disconnect is feed from a 30 amp breaker in service panel with # 10 wires, installer then pigtailed # 10 to line side lugs in AC disconnect and to line side lugs in the new 2 pole disconnect for snow melt cables. The snow melt disconnect has a 2 pole 20 amp GFCI breaker that then feeds the snow melt equipment. The snow melt cables have a built in thermostat that automatically shuts off the cables if the outdoor air temp is greater than 40 degrees. Also this is a residential single family home. Hope this helps I was not able to find anything in the 2011 NEC that would prevent this installation. Nor do I want too the whole house if finished and getting back to the service panel would be a pain, I think this is a ingenious way to get the job done without having to enter the house.

 

[kwired]

May be a little more info would help. The AC (not a heat pump) disconnect is feed from a 30 amp breaker in service panel with # 10 wires, installer then pigtailed # 10 to line side lugs in AC disconnect and to line side lugs in the new 2 pole disconnect for snow melt cables. The snow melt disconnect has a 2 pole 20 amp GFCI breaker that then feeds the snow melt equipment. The snow melt cables have a built in thermostat that automatically shuts off the cables if the outdoor air temp is greater than 40 degrees. Also this is a residential single family home. Hope this helps I was not able to find anything in the 2011 NEC that would prevent this installation. Nor do I want too the whole house if finished and getting back to the service panel would be a pain, I think this is a ingenious way to get the job done without having to enter the house.

The heat cable is likely self regulating and the amount of current it draws is related to the actual temperature of the cable itself. That means when it is coldest outside the cable is drawing the most current - the air conditioner is likely running the least and likely not at all. I still think the AC disconnect should probably contain overcurrent device for the AC and possibly the breaker for the de icing cable, although separate enclosures is acceptable.

I would hope they entered the home to turn the feed off before tapping onto the AC circuit

 

[Wyatt Earp]

I would like to thank all posters for their input it?s been a real help! I am the chief electrical inspector in my city and this job was tagged by one of my other inspectors but when pressed they could not come up with a specific code reference, which I always insist upon when writing up a correction.

 

[Sierrasparky]

Code refrences are easy!

What code do you go by?

1) cross sectional space for conductors in panel 312.8

2) Load on coductors.
a) see 210.19 (1) General " not less than the max load served"
b) see 220.18.(A) Motor operated loads - a/c plus the sum of the other loads.
I am sure if I can dig I can come up with more.

I do not see a automatc thermostat in a heat cable as a legitimate load transfer switch to alleveate using the sum of all loads.
I also do not see a creatve solution being a reason for allowing a non compliant method of wiring.
But then your mind is already made up!