New heat in the shop ..electric furnace help
Kicks "what" breaker?
The main in the fuse panel? How big is it
"Here's how" the majority of electric furnaces are setup for many years
Most electric furnaces are fed off MULTIPLE breakers in the fuse panel, as well as having some breakers right on / in the furnace
Generally, "they work" like so:
1....First a 20/30A (220-240V) circuit powers the controls, the blower, and usually, just one element
2....Next, depending on how big the furnace is, additional 40 or 50A breakers power the next sets of heating elements in sets of two
What I mean is, each element is "nominally" 5KW or about 20A or so draw.
40,000 BTU is not very big. A 5KW element is nominally 17,000 BTU
That would seem to be only two elements. In that case "it might be" that there is only one circuit, so one 40A breaker would be "marginal"
Other:
Breakers can develop loose connections both where they clip into the buss in the rear of the panel, and the wire set screw / connection. This creates HEAT which causes the breaker to trip
Also, breakers DO simply "get weak" or go bad for other reasons. So even if it's wired properly, with large enough wire, and enough breaker capacity, "it might be" you have a breaker going bad
A "standard tool" for every HVAC guy especially working on something like this is a clamp - on ammeter commonly called an "amprobe"
BE DARN CAREFUL messin' round in those. They operate off 220-240 which means that BOTH legs of the power are hot, and the control devices (relays or sequencers) ONLY SWITCH one leg. This means that EVERYTHING inside there is HOT at all times 120V to "ground."
Kicks "what" breaker?
The main in the fuse panel? How big is it
"Here's how" the majority of electric furnaces are setup for many years
Most electric furnaces are fed off MULTIPLE breakers in the fuse panel, as well as having some breakers right on / in the furnace
Generally, "they work" like so:
1....First a 20/30A (220-240V) circuit powers the controls, the blower, and usually, just one element
2....Next, depending on how big the furnace is, additional 40 or 50A breakers power the next sets of heating elements in sets of two
What I mean is, each element is "nominally" 5KW or about 20A or so draw.
40,000 BTU is not very big. A 5KW element is nominally 17,000 BTU
That would seem to be only two elements. In that case "it might be" that there is only one circuit, so one 40A breaker would be "marginal"
Other:
Breakers can develop loose connections both where they clip into the buss in the rear of the panel, and the wire set screw / connection. This creates HEAT which causes the breaker to trip
Also, breakers DO simply "get weak" or go bad for other reasons. So even if it's wired properly, with large enough wire, and enough breaker capacity, "it might be" you have a breaker going bad
A "standard tool" for every HVAC guy especially working on something like this is a clamp - on ammeter commonly called an "amprobe"
BE DARN CAREFUL messin' round in those. They operate off 220-240 which means that BOTH legs of the power are hot, and the control devices (relays or sequencers) ONLY SWITCH one leg. This means that EVERYTHING inside there is HOT at all times 120V to "ground."
