SYSTEM CHECK
Before Start-Up:
1. All wiring should be in accordance with local
codes.
2. Refrigerant lines should be properly sized.
3. Thorough evacuation and dehydration has been
performed.
4. The suction, discharge, and receiver service
valves must be open.
5. The system preferably include a liquid line filter
drier moisture indicator and suction filter.
6. Pour enough water into the drain pan to allow a
good check on drainage and seal the trap.
After Start-Up:
1. Check the oil level to be sure the oil charge is
correct.
2. On initial start up the fans do not start until coil
temperature is pulled down to approximately 25°F
(-4°C)
on the coil. Also, it is normal for the fan to
cycle a few times until the room temperature is
pulled down.
3. If necessary, temporarily by-pass fan delay control
(to run fans until room temp is lowered).
4. Be sure that the expansion valve is properly set to
provide the correct amount of superheat.
5. After the box temperature is close to reaching the
desired temperature, the evaporator superheat
must be checked and adjustment made if
necessary. In general, evaporators running with
a TD of 10°F
(5.6°C
) should have a superheat
reading of 6° to 8°F
(3.3°C to 4.4°C)
. For
evaporators with another T.D., the general rule is
that the superheat should be around 60 to
80% of T.D.
6. Heavy moisture loads are usually encountered
when starting the system for the first time.
This may cause a rapid build-up of frost on the
evaporator. During the initial pull down, we
suggest that the frost build-up be watched and
defrosted manually as required.
7. Observe that the system goes through at least
one complete DEFROST CYCLE.
PIPING
Refrigeration grade piping must be used for all field
refrigeration piping. Refrigerant line sizes are important
and
may not
be the same size as the coil connections.
Consult ASHRAE handbook or other similar reference
book for proper line sizing.
Refrigerant piping and control system should be designed
to prevent possible liquid slugging (from oil or refrigerant)
of the compressors on start-up after the defrost cycle.
Also, it should prevent oil logging and minimize refrigerant
pressure drop.
WIRING
Wire system in accordance with governing standards and
local codes. See data and wiring diagrams on pages 4 to
20 for typical wiring arrangement. Electrical wiring is to be
sized in accordance with minimum circuit ampacity rating
(MCA).
Size fuses used must not exceed the Maximum
Fuse Size ratings.
For ease of identifying the proper wiring terminal, unit
wiring is color coded and terminal block connections are
identified.
When
fan delay thermostats
(combination fan delay and
defrost termination) are installed, on start-up, the fans
do not operate until the coil temperature is reduced to
approximately 25
o
F
(-4°C)
. It is normal for the fans to
cycle a few times until the room temperature is brought
down. At higher evaporating temperatures this control
may not close and therefore should either be by-passed
temporarily or replaced with an adjustable type. (set for a
higher temperature cut-in point).
MAINTENANCE
The unit should be periodically inspected for any dirt or ice
build-up on the fin surface and cleaned if necessary with
a soft whisk or brush. Also ensure coils inner (and outer)
drain pans do not have any ice build-up from improper
defrost operation. When replacing heater elements first
remove heater retainer brackets and heater clips.
INSTALLATION INSTRUCTIONS
TPLP
60Hz
23/12/16
T30-TPLP-PDI-11
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