Control Transformer Primary Voltage Tappings; Compressor Heaters; Relief Valves; High Pressure Cutout - York YCWL0056SE Installation Operation & Maintenance

FORM 201.26-NM1
ISSUE DATE: 1/19/2018
Connect each of the earth grounds to the main protec-
tive earth ground terminals in the power sections.
Connect the control supply to the door interlocked
emergency stop device located in the common input
section, using the wire sizes detailed in Section 5.
Connect the earth ground to the main protective earth
terminal in the common input section.
Control Transformer Primary Voltage
Tappings
It is important to check that the correct primary tapping
has been used on the control transformer:
• With the supply to the unit isolated remove the lid
to the transformer box.
• Check that the tapping used conforms to the site
supply voltage. The two tappings are 342-424V
and 360-440V.

COMPRESSOR HEATERS

Compressor heaters are standard. If power is OFF
more than two hours, the crankcase heaters must be
energized for 18 to 24 hours prior to restarting a com-
pressor. This will assured that liquid slugging and oil
dilution does not damage the compressors on start.
JOHNSON CONTROLS

RELIEF VALVES

Relief valves are located on both the high and low pres-
sure side of the piping. High side relief valve pressure
setting is 560 PSIG.

HIGH PRESSURE CUTOUT

On 60 Hz chillers, a high pressure cutout is installed in
the discharge piping of each system. The cutout opens
at 500 PSI plus or minus 8 PSIG and automatically
closes at 375 PSIG plus or minus 10 PSIG.
On 50Hz chillers, all models will utilize a manual re-
set high pressure cutout of 503 PSIG (34.7 barg). On
chillers with compressors exceeding a swept volume
of 25L/sec, a second tool reset cutout is installed with
a cutout of 532 PSIG (36.7 barg). These cutouts con-
form to relevant requirements of Pressure Equipment
Directive PD 97/23/EC.
SECTION 4 – INSTALLATION
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