An Electric Heat Mistake

I started working as a tech when I was 17 years old, fresh out of trade school. My first winter out on my own, I went to a service call in an older part of Orlando, a part of town I had never worked in before. It was an especially cold winter that year, and the service call was for insufficient heat.

When I arrived, I found the system was an ancient GE straight cool system. After testing the system, I found that the system had a 10kw heater, but only 5kw was working. After a closer look, I discovered that 5kw of the heat was disconnected. This was no problem for me; wiring was always my specialty! I grabbed some #12 stranded and had that puppy heating in no time.

Problem…

#1 – It smoked like a chimney and set off every alarm in the house

#2 – Once I got the doors and windows open and the smell cleared out as best I could, it got me thinking… How long has it been since that second 5kw was connected?

When I looked closer, I saw that the feed wire going to the air handler was only #10—then it dawned on me.

The REASON they had one-half of the heat disconnected was that the breaker and wire size were only rated for 5kw. “Why did they have a 10kw?” you might ask. It's likely what some other tech had on the truck, and they figured if they disconnected one-half, it would be safe.

Lessons learned:

#1 – Never assume that a system was installed properly in the first place, and keep an eye out for proper feed wire size.

#2 – Don't use improperly rated heat strips or other rated parts and simply make an “alteration.” When the next technician arrives, they likely won't understand what you did. At best, you confuse them. At worst, you kill them.

—Bryan

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4 responses to “An Electric Heat Mistake”

  1. How about doing an article on correct sizing of heater banks for doing de-humidification with Heat/Cool.

  2. On the heating element on the picture, that’s two seperate strips right? I ran into one exactly like that one and it was wired as if one strip. They had only one limit on what appeared to be two strips. It tripped me all up.

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