Periodic maintenance - as
needed
Replacing the main control
board
When it is necessary to replace the main control
board, the unit configuration must be restored
from a backup file. For instructions, refer to the
Backup Function
and
Restore Function
sections in the
Tempmaster Omni
™
Premier 25 Ton to 80 Ton Rooftop
Units R-410A Start-Up and Operation Guide (5881376-
TSG-A)
.
When unable to back up the unit configuration
from the current main control board, download the
correct backup file by scanning the QR code on the
unit with the RTUToolkit app, or contact Product
Technical Support.
Phase monitor checks and
adjustments
If the phase monitor fails to properly operate, check
that all three voltages are present and are the
correct voltage level and phase rotation.
Check all fuses and verify that all wiring connections
are correct.
To adjust the low voltage trip point just below
the nominal phase-to-phase voltage, rotate the
adjustment control fully clockwise, or until the red
(TRIP) indicator illuminates.
Slowly rotate the adjustment control
counterclockwise, just until the green (NORM)
indicator illuminates. At this point, the phase
monitor is the most sensitive to irregular power
line conditions. If nuisance tripping occurs,
rotate the adjustment control slightly farther
counterclockwise.
Compressor replacement
When it is necessary to replace a compressor in the
unit, follow these steps:
1. Determine if the compressor failure was
mechanical or electrical.
a. When the failure is electrical, an oil
analysis is strongly recommended to
see if the oil has become acidic.
- When the oil is acidic, it is
strongly recommended to
replace both compressors
on the circuit if they are a
tandem set.
b. When the failure is mechanical, an
oil analysis may be necessary to
determine the amount of debris in the
system.
2. Always replace the in-line or replaceable core
filter driers.
3. Replace the compressor contactor.
4. After replacing the compressor, pull the entire
system into a deep vacuum.
Note:
A deep vacuum is considered to be
less than 500 microns.
5. If the failure was electrical and the oil was
determined to be acidic, use fresh refrigerant
to recharge the system.
Tempmaster
®
Omni™ Premier 25 Ton to 80 Ton Rooftop Units Installation and Maintenance Guide
105
Tempmaster
