York Millennium YCAJ150, Installation Operation & Maintenance, Page: 93 / 116

FORM 150.65-NM4
93 YORK INTERNATIONAL
FIELD INSTALLATION
If it becomes necessary to field install the Hot Gas
(Loadminder) Option, two kits are required. The part num-
bers of the kits are 375-04249-001 and 471-01232-101.
The 471-01232-101 kit consists of a second Relay Out-
put Board. It is not required if two Relay Boards are al-
ready installed in the control panel. If the 375-04249-001
kit is not available, the following parts should be ordered
separately.
DISCHARGE PRESSURE READOUT OPTION
The Discharge Pressure Readout Option P/N 471-01232-
131 allows the user to obtain control panel displays of
discharge pressure. Additionally, other displays such as
fault information will then hold relevant discharge pres-
sure information useful in diagnosing problems.
The discharge pressure unloading feature also becomes
usable when this option is installed (Page 44) as well as
fan cycling by discharge pressure.
Fan cycling by discharge pressure sometimes becomes
ITEM QTY PART # DESCRIPTION
1 1 375-00431-025 SOL. VALVE
2 1 375-00431-026 SOL. VALVE
3 2 075-03742-000 SUPPORT
4 1 075-04281-000 PIPE CONN.
5 4 066-83964-000 CLAMP
6 2 075-04286-000 PIPE CONN.
7 4 066-88928-000 CLAMP
8 4 023-00200-000 REDUCER
9 1 075-04200-000 PIPE CONN.
10 1 075-04283-000 PIPE CONN.
11 1 075-04202-000 PIPE CONN.
12 1 075-03781-000 PIPE CONN.
13 1 075-04284-000 PIPE CONN.
14 4 021-16161-000 SCREW
15 20 021-16136-000 SCREW
16 4 021-16210-000 LOCKWASHER
17 2 023-08576-000 TEE
18 4 021-16151-000 HEX NUT
19 2 023-09743-000 E11
20 1 075-04285-000 TUBING
22 1 075-04282-000 PIPE CONN.
23 2 031-01117-000 SUPPRESSOR
24 2 023-05299-000 CLAMP
25 2 021-08381-000 SCREW
26 2 021-00451-000 HEX NUT
27 2 021-01148-000 LOCKWASHER
30 1 075-04201-000 PIPE CONN.
32 5 023-00061-000 COUPLING
33 4 075-04519-000 BRACKET
XX 1 075-04249-000 DRAWING
necessary, if ambient temperature cycling of fans causes
low suction pressure faults due to unusual operating
conditions or chiller location problems. Fan cycling by
discharge pressure only, allows higher discharge pres-
sures which in turn raises suction pressure by permit-
ting better operation of the thermal expansion valve. To
convert to discharge pressure cycling, the micro panel
must be programmed for DISCHARGE PRESSURE FAN
CONTROL (See Page 38). Fan cycling will operate as
indicated in Table 3.
TABLE 3 – FAN CYCLING
The kit consists of discharge pressure transducers for
each system, wire harnesses, and associated mounting
hardware.
HIGH AMBIENT OPTION
The High Ambient Option consists of two kits, P/Ns 471-
01232-131 and 475-23850-000. The option allows opera-
tion of the chiller in ambients up to 115°F (46.1°C). Typi-
cally, standard operation is limited to 105°F (40.6°C).
High ambient operation is accomplished by discharge
pressure unloading to assure that the chiller does not
fault due to the high pressure cutout opening during high
temperature operation. A sun shield is also installed on
the control panel to prevent direct sunlight from over-
heating the control panel causing subsequent malfunc-
tion of the electromechanical and electronic components
in the control panel. Additionally, actual discharge pres-
sure readouts can now be obtained from the micro panel.
Discharge Pressure unloading allows the microproces-
sor to unload a compressor when the discharge pres-
sure approaches a point nearing the discharge pressure
cutout. This assures that the system does not shut down
completely if the cutout were to open. See Page 44 for
programming the unloading pressure.
Fan cycling by discharge pressure is also available when
this option is installed (See DISCHARGE PRESSURE
READOUT OPTION this page), however it is of little use
in areas where ambients are generally high and stan-
dard temperature control of the fans provides good con-
trol and maximum efficiency.
SYS FAN CONTACTORS ON OFF
1 & 3 REV
(Optional 9M & 10M
320 PSIG 120 PSIG
Low Ambient)
(2.2 mPa) (827.4 kPa)
1
2 & 4 6M & 8M
340 PSIG 120 PSIG
(2.3 mPa) (827.4 kPa)
1 & 3 FWD 5M & 7M
360 PSIG 140 PSIG
(2.5 mPa) (965.3 kPa)
5 & 7 REV
(Optional 15M & 16M
320 PSIG 120 PSIG
Low Ambient)
(2.2 mPa) (827.4 kPa)
2
6 & 8 12M & 14M
340 PSIG 120 PSIG
(2.3 mPa) (827.4 kPa)
5 & 7 FWD 11M & 13M
360 PSIG 140 PSIG
(2.5 mPa) (965.3 kPa)