Initial Checks; Motor And Blower - Weather-Rite XT112 Installation, Operation & Service Manual

S XT I , O
ERIES NSTALLATION PERATION AND

23.1 Initial Checks

When encountering any abnormal operation or fault conditions of the equipment, all troubleshooting should
start with the following initial checks. If a problem is discovered in these initial checks it must be corrected
before moving on in the trouble shooting.
1. Compare voltage and phase of supply power on site with rating plate information.
2. Review wiring between remote panel and control panel. Do the electrical connections match the sup-
plied wiring diagram?
3. Compare gas type and supply pressure on site with rating plate information.
4. Check for proper blower rotation on air handler and any exhaust blowers.
• Blowers powered with a three phase motor can be reversed by swapping any two incoming power
legs. For blowers powered by a single phase motor refer to the motor rating plate for reversing
instructions.

23.2 Motor and Blower

PROBLEM
Motor does not operate
Blower does not operate
80
S M
ERVICE ANUAL
POSSIBLE CAUSE
Main disconnect switch is OFF
Blown fuse(s) in disconnect
Blown fuse(s)/breaker tripped in control transformer Replace fuse(s)/reset breaker (with
Fan switch on
Optional: Damper does not open
Motor starter (contactor) does not operate.
Tripped motor overload. Power out to MUA motor
when motor starter is energized?
Optional: Low limit switch set to high
Belts broken or loose?
Loose motor or blower sheaves (pulleys)
Blower bearings, do they turn freely?
SOLUTION
Turn disconnect to ON
Replace fuse(s)
disconnect off)
Check wiring between remote panel
and air handler. Replace switch.
Check that damper is not obstructed
Check that linkage is tight and
secure
Replace damper actuator
Replace starter
Reset
Check for proper FLA setting
Replace overload
If applicable: Tighten screws on
heater packs or overload.
Re-adjust low limit switch setting
Replace/tighten belts
Reinstall and properly torque set-
screws
Replace bearing(s)