York YLAA Operation Manual page 11

Equipment Overview (Cont'd)
JOHNSON CONTROLS
Motors – The fans are driven by Totally Enclosed Air-Over, squirrel-cage type, current pro-
tected motors. They feature ball bearings that are double-sealed and permanently lu bricated.
UNIT CONTROL SYSTEM
The YLAA chiller is designed with an intelligent control system that operates the chiller
automatically with maximum reliability, safety and ease of use. The controls are factory
tested and with as little user input as a chilled liquid setpoint the chiller will operate to meet
the load demand.
The control system includes native BACnet MS/TP, Modbus and N2 communications, with
LON protocol served through an optional eLink communications card.
The operating program is stored in non-volatile memory (EPROM), so power failures and
battery discharge will not require reprogramming the chiller. Programmed setpoints are
retained in lithium battery-backed RTC memory for five years minimum.
Unit alarm contacts are standard. Contacts for remote chilled liquid temperature reset
and two steps of demand load limiting are also standard, for projects without BAS or for
redundancy.
ON/OFF
SWITCH
TERMINAL
BLOCK
DISPLAY
KEYPAD
MICROBOARD
TRANSFORMER
LD18429
FUSES
FORM 150.72-EG6 (516)
LD18428
CONTROL
11