*Mike
December 12th, 2003, 09:21 AM
#76: Replacing an electric baseboard thermostat Author: Mike, Posted: Wed Nov 26, 2003 12:23 am
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Hi,
I bought a new thermostat for my bedroom which will control two baseboard electric heaters. The two heaters are rated as follows:
heater 1: 240 volts @ 1000 Watts
heater 2: 240 volts @ 1500 Watts
The new thermostat is rated for 240V @ 3800 watts.
My dilema is how to use the wiring connected to the old 4 wire DPST thermostat for the new 4 wire thermostat. The new thermostat has two poles - one for the source and one for the load.
The existing wiring has me baffled since there are actually 6 wires. Connected to the red wires on the DPST thermostat are two pairs of two. One pair is white and the other is black and each pair measues 110v. Connected to the black wires of the DPST are a single white and a single black wire respectively.
Now, if I separate the paired wires (white or black) and measure the volatge between these 2 wires I see 100v. Measuring only one of the wires when compared to ground shows 110v and the other has zero.
So, I really need help in understanding how to go from the old DPST to the new dual pole switch requiring a 240 source and the resistive load.
Regards,
Mike
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#128: Author: wannabee, Posted: Thu Nov 27, 2003 9:56 am
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Not sure if following you right? You must have 240 across one pair of wires? If 6 wires, would think pair with 240v is feed(scorce) and other 4 would be heaters 1 pair each. 240 scorce to line side and remaining 4 (LOAD)to load side. Sounds like you have only S/P thermostat. You must have D/P breaking both legs of power scorce. Reply
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#135: Author: Wgoodrich, Posted: Thu Nov 27, 2003 12:40 pm
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Wannabbee is correct, by NEC rules you are required for the thermostat to have two line and two load connections one for each hot wire. Both hot wires are required to be turned on and off by that thermostat. The old thermostat is wired correctly you bought the wrong replacement thermostat.
Wg
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Hi,
I bought a new thermostat for my bedroom which will control two baseboard electric heaters. The two heaters are rated as follows:
heater 1: 240 volts @ 1000 Watts
heater 2: 240 volts @ 1500 Watts
The new thermostat is rated for 240V @ 3800 watts.
My dilema is how to use the wiring connected to the old 4 wire DPST thermostat for the new 4 wire thermostat. The new thermostat has two poles - one for the source and one for the load.
The existing wiring has me baffled since there are actually 6 wires. Connected to the red wires on the DPST thermostat are two pairs of two. One pair is white and the other is black and each pair measues 110v. Connected to the black wires of the DPST are a single white and a single black wire respectively.
Now, if I separate the paired wires (white or black) and measure the volatge between these 2 wires I see 100v. Measuring only one of the wires when compared to ground shows 110v and the other has zero.
So, I really need help in understanding how to go from the old DPST to the new dual pole switch requiring a 240 source and the resistive load.
Regards,
Mike
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#128: Author: wannabee, Posted: Thu Nov 27, 2003 9:56 am
----
Not sure if following you right? You must have 240 across one pair of wires? If 6 wires, would think pair with 240v is feed(scorce) and other 4 would be heaters 1 pair each. 240 scorce to line side and remaining 4 (LOAD)to load side. Sounds like you have only S/P thermostat. You must have D/P breaking both legs of power scorce. Reply
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#135: Author: Wgoodrich, Posted: Thu Nov 27, 2003 12:40 pm
----
Wannabbee is correct, by NEC rules you are required for the thermostat to have two line and two load connections one for each hot wire. Both hot wires are required to be turned on and off by that thermostat. The old thermostat is wired correctly you bought the wrong replacement thermostat.
Wg
