Unitary products group CPH 060, Installation & Operation Instructions

Page: 17 / 24

FORM 145.14-IOM1 (908)
17
JOHNSON CONTROLS
START-UP AND OPERATION
Prior to starting unit for the first time,
turn the thermostat system switch to
OFF - or raise the cooling setpoint to the
highest temperature to prevent the unit
from starting, then close the electrical
disconnect switch.
Start unit and check rotation of fans and compressors.
Scroll compressors will only compress in one rotational
direction. Three phase compressors will rotate in either
direction depending upon phasing of the power. Since
there is a 50-50 chance of connecting power in such a
way as to cause rotation in the reverse direction, it is
important to ensure proper rotation direction is achieved
when the system is installed and operated.
Verification of proper direction is made by observing
that suction pressure drops and discharge pressure
rises when the compressor is energized. Reverse rota-
tion also results in an elevated sound level as well as
substantially reduced current draw.
There is no negative impact on durability caused by
operating three phase Scroll compressors in the re-
versed direction for a short period of time (under one
hour). However, after several minutes of operation the
compressors internal protector will trip.
If opposite rotation is needed, disconnect and reverse
any two leads of the three phase supply. Reconnect
power and observe for correct rotation.
Observe unit operation and check for unusual noise or
vibration.
Ref. Charge 5 TON 8 TON 10 TON
No. of Circuits 1 2 2
Per Circuit (lb) 4.625 4.188 5.125
High Low
Cut Out (PSIG) 400 25
Cut In (PSIG) 275 60
PRESSURE SWITCH SETTINGS - ALL MODELS