JOHNSON CONTROLS
109
SECTION 7 – UNIT CONTROLS
FORM 150.27-NM1
ISSUE DATE: 09/30/2015
7
If the microprocessor is programmed for CURRENT
FEEDBACK ONE PER UNIT under the OPTIONS
key, the display will show up as the first display prior
to the SYS 1 displays. Total chiller current is displayed
as shown below:
U N I T A M P S = 5 4 . 0
V O L T S = 1 . 2
If the microprocessor is programmed for CURRENT
FEEDBACK NONE, no current display will appear.
S Y S X R U N T I M E
X X - X X - X X - X X D - H - M - S
S Y S X C O M P S T A T U S
1 = X X X 2 = X X X 3 = X X X
S Y S X L L S V I S O N
H O T G A S S O L I S O F F
S Y S X A M P S = 3 6 . 0
V O L T S = 0 . 8
S Y S X F A N S T A G E 3
The preceding five messages will appear sequentially,
first for system 1, then for system 2.
The first message indicates the system and the associ-
ated compressors which are running.
The second message indicates the system run time in
days – hours – minutes – seconds. Please note that this
is not accumulated run time but pertains only to the
current system cycle.
The third message indicates the system, and whether
the liquid line solenoid or EEV pilot solenoid and hot
gas solenoid are being turned on by the microboard.
Please note that hot gas is not available for system 2, so
there is no message pertaining to the hot gas solenoid
when system 2 message is displayed.
The fourth message indicates the stage of condenser
fan operation that is active. This message does not ap-
ply to a YCRL chiller and is displayed as a result of
the use of software common to YCA, YCRL and YCW
chillers.
E V A P O R A T O R H E A T E R
S T A T U
S I S = X X X
This display indicates the status of the evaporator
heater. The evaporator heater is controlled by ambient
air temperature. When the ambient temperature drops
below 40 °F the heater is turned ON. When the tem-
perature rises above 45 °F the heater is turned off. An
under voltage condition will keep the heater off until
full voltage is restored to the system.
E V A P
O
R
A T
O
R W
A T E
R
P U
M
P S T A T U
S = X X X
X
The evaporator pump dry contacts are energized when
any compressor is running, or the unit is not OFF on
the Daily Schedule and the UNIT switch is ON, or the
unit has shutdown on a Low Leaving Chilled Liquid
fault. However, even if one of above is true, the pump
will not run if the micro panel has been powered up for
less than 30 seconds or if the pump has run in the last
30 seconds to prevent pump motor overheating.
E V A P
P U M P T O T A L R U N
H
O
U
R
S = X X X X X
The Evaporator Pump Total Run Hours display indi-
cates the total pump run hours. Total hours continu-
ally increments similar to Compressor Run Hours. If
dual pumps are fitted, run hours indicates total hours
on both pumps.
A C T I V E R E M O T E C T R L
N
O
N
E
There are several types of remote systems that can be
used to control or monitor the unit. The following mes-
sages indicate the type of remote control mode active:
•
NONE – no remote control active. Remote moni-
toring may be via ISN.
•
ISN – YORK Talk via ISN allows remote load
limiting and temperature reset through an ISN
system.
•
LOAD LIM – Load limiting enabled using con-
tact closure.
•
PWM TEMP – EMS temperature reset
