York YCAL Series Installation Operation & Maintenance page 109

FORM 150.66-NM3
ISSUE DATE: 09/25/2020
This display indicates the current LEAD system. In this
example system 2 is the LEAD system, making system
1 the LAG system. The LEAD system can be manu-
ally selected or automatic. Refer to the programming
under the "OPTIONS" key. The Lead System display
will only appear on a two system unit.
A unit utilizing hot gas bypass should
be programmed for MANUAL with
system 1 as the lead system. Failure
to do so will prevent hot gas operation
if system 2 switches to the lead system
when programmed for AUTOMATIC
LEAD/LAG.
E V A P P U M P
E V A P H E A T E R
This display indicates the status of the evaporator pump
contacts and the evaporator heater.
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.
The evaporator heater is controlled by ambient air tem-
perature. When the ambient temperature drops below
40°F the heater is turned on. When the temperature
rises above 45°F the heater is turned off. An under volt-
age condition will keep the heater off until full voltage
is restored to the system.
A C T I V E R E M O T E
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 monitoring
may be via ISN.
ISN – YORK Talk via ISN allows remote load lim-
iting and temperature reset through an ISN
system.
*LOAD LIM – load limiting enabled. Can be ei-
ther stage 1 or stage 2 of limiting.
JOHNSON CONTROLS
I S O N
I S O F F
C T R L
*PWM TEMP – EMS-PWM temperature reset
*See SECTION 8 - UNIT OPERATION
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
V O L T S
If the microprocessor is programmed for CURRENT
FEEDBACK NONE, no current display will appear.
S Y S X C O M P
1 = X X X 2 = X X X
S Y S X R U N
X X - X X - X X - X X
S Y S X L L S V
H O T G A S S O L
S Y S X F A N
S Y S X A M P S
V O L T S
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. 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.
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.
SECTION 7 - UNIT CONTROLS
= 5 4 . 0
= 1 . 2
S T A T U S
3 = X X X
T I M E
D - H - M - S
I S O N
I S O F F
S T A G E 3
= 3 6 . 0
= 0 . 8
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