McQuay Cabinet Heater

Jalen_Jalen2006

Cabinet Heater w hot water coil ran for a couple days says customer and, then just died. Stopped running after making loud ruckus, I’ve messed with a few of these usually you can get them to run, turn down the temperature controller which dictates when the fan comes on. Or it’s a bad capacitor or the motor is just dead or the blower wheel is out alignment and it’s rubbing. This one, I have power at all my switches all my contacts are closing. Though absolutely nothing is happening. My supply and return to the unit are hot. I deduced that it’s a bad speed selector because, when I switch speeds and check power going to the motor according to the schematic I should have line voltage at a specific connection based on speed, I only get 26 volts. What do you guys think?

1. what type of switch is that?

Steamhead

That's a motor switch with a built-in overload protector. Like a motor starter without the remote control station. Usually if you turn these off, wait a minute or so and turn them back on, they will reset.

EBEBRATT-Ed

On the left side of the switch one power wire comes in on L! drops down and feets the top of the heater coil then comes out the bottom of the heater coil and feeds T1 which goes to the motor

On the right side power comes in L2 and goes out on T2 to the motor.

You should have continuity with your meter set to OHMS withe the POWER OFF through both sides of the switch with the switch closed and the heater element reset.

You may have to push the switch hard up or down to reset the overload.