I'm currently working on the control box for my HERMS system and getting ready to wire up the transformer to step the voltage down to 24 for the gas valve. I've listed the transformer and gas valve I'm using below. The installation instructions from Honeywell for the transformer say that it cannot be mounted in a plastic enclosure, only metal. I'm trying to figure out why that is and Honeywell hasn't been much help in getting an answer. My guess is that it is due to one of two things:
1. The transformer can get hot, and so it may melt the plastic container.
2. The transformer does not have a ground wire hookup on it anywhere (primary or secondary side) and so in order to get a circuit to ground they are saying to use a metal box, which would itself be grounded. Since the transformer would be screwed to the metal box, then maybe that is what provides it a path to ground.
I've been trying to figure out if a transformer like this even needs to be grounded and haven't been able to find a definitive answer. I'm using a plastic box for my control panel and don't want to scrap that and start over with a metal one unless it's totally necessary. Anybody have any guidance they can offer?
Transformer:
https://www.supplyhouse.com/Honeywell-AT140A1042-Universal-Mount-Transformer-13620000-p
Gas Valve:
https://www.supplyhouse.com/sh/control/product/~product_id=VR8200A2132
1. The transformer can get hot, and so it may melt the plastic container.
2. The transformer does not have a ground wire hookup on it anywhere (primary or secondary side) and so in order to get a circuit to ground they are saying to use a metal box, which would itself be grounded. Since the transformer would be screwed to the metal box, then maybe that is what provides it a path to ground.
I've been trying to figure out if a transformer like this even needs to be grounded and haven't been able to find a definitive answer. I'm using a plastic box for my control panel and don't want to scrap that and start over with a metal one unless it's totally necessary. Anybody have any guidance they can offer?
Transformer:
https://www.supplyhouse.com/Honeywell-AT140A1042-Universal-Mount-Transformer-13620000-p
Gas Valve:
https://www.supplyhouse.com/sh/control/product/~product_id=VR8200A2132