Specifications

YORK INTERNATIONAL 39
FORM 160.48-O1
SOLID STATE STARTER (OPTIONAL)
The Solid State Starter is a reduced-voltage liquid cooled
starter that controls and maintains a constant current
flow to the motor during start-up. The starter is mounted
on the chiller. The power wiring from the starter to the
motor and from the starter control transformer to the
Control Center is factory wired and tested. Available for
200-600V-3Ph-60/50Hz power; 2 or 3 barrel lug connec-
tions per phase are provided on the starter. The starter
enclosure is NEMA Type1 and is provided with a hinged
door with lock and key.
VARIABLE SPEED DRIVE (OPTIONAL)
A 460V-3ph-60/50Hz Variable Speed Drive can be fac-
tory packaged with the chiller. It is designed to vary the
compressor motor speed and prerotation vane position
by controlling the frequency and voltage of the electri-
cal power to the motor. Operational information is con-
tained in Form 160.00-O1. The control logic automati-
cally adjusts motor speed and compressor prerotation
vane position for maximum part load efficiency by ana-
lyzing information fed to it by sensors located through-
out the chiller.
SECTION 5
OPERATIONAL MAINTENANCE
USE OF PUMP ASSISTED TURBOGUARD PURGE UNIT
PURGING THE SYSTEM
To assure satisfactory operation, it is important that
these systems be kept free of moisture-laden air and
noncondensible gases. Air in the system usually col-
lects in the condenser, blanketing some of the con-
densing surface, causing the discharge pressure and
temperature to rise, resulting in high operating costs
and possibly shutdown of the system by the high pres-
sure cutout. Moisture in the system causes acid for-
mation which is destructive to internal system parts.
A purge unit is furnished to automatically remove the
mixture of noncondensible gases and refrigerant from the
top of the condenser, expel the noncondensibles to the
atmosphere and return the refrigerant to the system.
IMPORTANT
The purge unit operates continuously only when
the system is in operation.
OPERATION
Purge operation is as follows: There is a fill and drain
cycle which is controlled via the action of the tank float
switches. The oil boost pump raises the oil supply pres-
sure to the purge tank to enable exhaust release at 90
PSIA. When an exhaust is made, the tank pressure will
drop from 90 to 80 PSIA. The pump is also used in the
drain portion of the purge cycle to pump out the purge
tank. This provides for uniform purge cycle duration. The
oil supply to the purge tank is taken downstream from
the chiller oil cooler in order to provide cool oil to the
tank and increase refrigerant separation efficiency. If the
purge air exhaust solenoid valve tails to open at 90 PSIA,
the power to the pump will be cut off at 105 PSIA with
the high pressure cutout switch. Manual reset is required
in order to re-energize the boost pump.
START-UP
1. Place the control panel in “PROGRAM” operating
mode as follows:
a. Press "Access Code" key.
b. This is displayed:
day
ENTER VALID ACCESS CODE
c. Using "Entry" keys enter the special service ac-
cess code. (See Section 2)
d. As each digit is entered, the characters Y O R K
are displayed.
NOTE: If digits other than the correct digits are
entered, Y O R K is still displayed.
e. Press the “ENTER” key.