York YK-EP B Operation & Maintenance Manual page 212

SECTION 5 - SERVICE
The Anti-recycle timer must never be
disabled unless advised by YORK factory.
Power Failure Restart – Determines the course of ac-
tion required to restart the chiller, if a power failure
occurs while the chiller is running. Selections are:
1. Manual – Requires a manual reset after power is
restored. The chiller cannot be started until the
operator moves the keypad Start-Run-Stop/Reset
rocker switch to the stop/reset position.
2. Auto – Chiller will automatically restart when
power is restored.
Coastdown – Determines the "Coastdown" duration
(oil pump run duration after shutdown) and whether
the "Motor Controller – Loss of Current" check and
anti-recycle function is performed while the chiller is
running. Selections are:
1. Standard – Electric motor applications. When
STANDARD is selected, the Coastdown Time
setpoint appears. This setpoint is used to set the
duration over the range of 240 (default) to 900
seconds or 150 (default) to 900 seconds as de-
termined by the selection made for the Chiller
Style/Compressor setpoint (on the OPERATIONS
Screen).
2. Enhanced – "Coastdown" is 15 minutes in dura-
tion. "Motor Controller - Loss of Current" check
and anti-recycle function is not performed since
there is no motor current.
Pre-run – Determines the duration of the "System Pre-
lube" period. Selections are:
1. Standard – "System Pre-lube" is 50 seconds in
duration.
2. Extended – "System Pre-lube" is 180 seconds in
duration.
Oil Pump Package – Configures the program for ei-
ther Variable Speed Drive Oil Pump or Fixed Speed
Oil Pump. Chillers equipped with the Variable Speed
Drive Oil Pump have a Program controlled Oil Heater
and a different complement of solenoid valves than
chillers equipped with a Fixed Speed Oil Pump. A de-
scription of the two Oil Pumps is as follows:
212
1. Variable Speed – configures the program to oper-
ate the Variable Speed Drive Oil Pump, the Oil
Heater (maintains oil temperature 50°F above
condenser saturation temperature) and the Oil Re-
turn and Liquid Line (J compressors only) sole-
noid valves are connected in parallel to TB1-61.
2. Fixed Speed – Configures the program to operate
the fixed speed Oil Pump and the following sole-
noid valves:
• TB1-61 Oil Return and Liquid Line connect-
ed in parallel
Motor Communications Protocol (VSD applications
(VSD and Style B LCSSS applications)
Only displayed when Motor Drive Type setpoint above
is selected as "VSD-60Hz", "VSD-50Hz" or "SSS-
Mod B". Allows the Service technician to enable the
appropriate serial communications port for commu-
nications with the Style B Liquid Cooled Solid State
Starter (LCSSS) or Variable Speed Drive (VSD). Early
vintage Style B LCSSS and VSD communicate with
the microboard using YORK protocol (COM 5 (J15)).
Later vintage units use Modbus protocol (COM 2
(J13)).
The protocol selection enables the appropriate commu-
nications port:
• YORK enables COM 5 A(J15)
• Modbus enables COM 2 (J13)
Selection required is based on the hardware and inter-
face that is present. The chiller must be stopped with
the START-RUN-STOP/RESET switch in the STOP/
RESET position to change this setpoint. A description
of the two protocols is as follows:
1. YORK – Enables COM 5 (J15) serial port. On
Variable Speed Drive applications, used when the
microboard is interfaced to the VSD via the ACC
Board. On Style B Liquid Cooled Solid State
Starter applications, used when the microboard
is interfaced to the LCSSS Logic/Trigger Board
TB2.
2. Modbus – Enables COM 2 (J13) serial port.
• VSD Applications – Used when the ACC
Board is not present and the microboard is
interfaced directly to VSD Logic Board 031-
02506 (J16).
FORM 160.87-OM1
ISSUE DATE: 8/24/2018
JOHNSON CONTROLS