York YCWL0056SE Installation Operation & Maintenance page 112

SECTION 6 – COMMISSIONING
C. POWER CHECKS
(POWER ON - UNIT SWITCHED OFF)
1. Apply 3-phase power and verify its value. Voltage
imbalance should be no more than 2% of the aver-
age voltage. .............................................................
2. Apply 120VAC and verify its value on the terminal
block in the power panel. Make the measurement
between terminals 5 and 2 of CTB2. The voltage
should be 120VAC +/- 10%. .....................................
3. Program/verify the
gram Setpoints, and Unit Options. Record the
values below (see sections on Setpoints and
Unit Keys in IOM for programming instruction) .
OPTIONS
Display Language
Sys 1 Switch
Sys 2 Switch
Chilled Liquid
* Ambient Control
Local/Remote Mode
Control Mode
Display Units
* Lead/Lag Control
* Fan Control
Manual Override
Current Feedback
** Soft Start
** Unit Type
** Refrigerant Type
** Expansion Valve Type
COOLING SETPOINTS
Cooling Setpoint
Range
EMS-PWM Max. Setpoint
PROGRAM
Discharge Pressure Cutout
Suct. Pressure Cutout
Low Amb. Temp. Cutout
Leaving Liquid Temp. Cutout
Anti-Recycle Time
Fan Control ON Pressure
Fan Differential OFF Pressure
Total # of Compressors
* Number of Fans/System
* Unit/Sys Voltage
Unit ID
* Not on All Models
** Viewable Only
112
Cooling Setpoints, Pro-
N/A
N/A
N/A
N/A
4. Put the unit into Service Mode (as described under the
Control Service and Troubleshooting section) and cy-
cle each condenser fan to ensure proper rotation. .
5. Prior to this step, turn system 2 OFF and system 1
ON (refer to Option 2 under Unit Keys section for
more information on system switches). Connect a
manifold gauge to system 1 suction and discharge
service valves. ........................................................
Place the Unit Switch in the control panel to the ON
position. As each compressor cycles ON, ensure
that the discharge pressure rises and the suction
pressure decreases. If this does not occur, the com-
pressor being tested is operating in the reverse di-
rection and must be corrected. After verifying prop-
er compressor rotation, turn the Unit Switch to "OFF,"
The chilled liquid setpoint may need to
be temporarily lowered to ensure all com-
pressors cycle ON.
This unit uses scroll compressors which
can only operate in one direction. Failure
to observe this will lead to compressor
failure.
6. Turn system 1 OFF and system 2 ON (refer to Op-
tion 2 under Unit Keys sections for more informa-
tion on system switches).
Place the Unit Switch in the control panel to the ON
position. As each compressor cycles ON, ensure
that the discharge pressure rises and the suction
pressure decreases. If this does not occur, the com-
pressor being tested is operating in the reverse di-
rection and must be corrected. After verifying prop-
er compressor rotation, turn the Unit Switch to OFF.
The chilled liquid setpoint may need to
be temporarily lowered to ensure all com-
pressors cycle ON.
FORM 201.26-NM1
FORM 201.26-CL1
ISSUE DATE: 1/19/2018
ISSUE DATE: 3/28/2013
JOHNSON CONTROLS