Diagnostic Name Affects
Target
Severity
Persistence Active Modes
[Inactive Modes]
Criteria
Reset
Level
Low Evaporator Rfgt
Temp Circuit 1: Unit
Off
Chiller
Special Ac-
tion
NonLatch
Unit in Stop Mode,
or in Auto Mode and
No Ckt's Energzd
[Any Ckt Energzd]
The respective circuit’s LERTC Integral
was seen to be > 0 while the chiller is
in the Stop mode, or in Auto mode with
no compressors running for at least one
minute. The LERTC integral is increased
if the Evap Refrigerant Pool Temp is be-
low the value of the Low Evap Rfgt Temp
2°F. Energize Evap Water Pump
and Off-Cycle Freeze Avoidance Request
Relay until diagnostic auto resets, then
return to normal evap pump control and
de-energize the Freeze Avoidance Re-
quest. Automatic reset occurs when the
respective Evap Rfgt Pool Temp rises 4°F
(1.1°C) above the LERTC cutout setting
for 1 minute and the Chiller Off LERTC
Integral = 0.. This diagnostic even while
active, does not prevent operation of
either circuit.
Remote
Low Evaporator Rfgt
Temp Circuit 2: Unit
Off
Chiller
Special Ac-
tion
NonLatch
Unit in Stop Mode,
or in Auto Mode and
No Ckt's Energzd
[Any Ckt Energzd]
The respective circuit’s LERTC Integral
was seen to be > 0 while the chiller is
in the Stop mode, or in Auto mode with
no compressors running for at least one
minute. The LERTC integral is increased
if the Evap Refrigerant Pool Temp is be-
low the value of the Low Evap Rfgt Temp
2°F. Energize Evap Water Pump
and Off-Cycle Freeze Avoidance Request
Relay until diagnostic auto resets, then
return to normal evap pump control and
de-energize the Freeze Avoidance Re-
quest. Automatic reset occurs when the
respective Evap Rfgt Pool Temp rises 4°F
(1.1°C) above the LERTC cutout setting
for 1 minute and the Chiller Off LERTC
Integral = 0.. This diagnostic even while
active, does not prevent operation of
either circuit.
Remote
Evaporator Water
Flow Overdue
Chiller
Normal
NonLatch
Estab. Evap. Water
Flow on going from
STOP to AUTO or
Evap Pump Over-
ride.
within 20 minutes of the Evaporator
water pump relay being energized in
normal “Stop” to “Auto” transition. If
the pump is overridden to “On” for cer-
tain diagnostics, the delay on diagnostic
callout shall be only 255 seconds. The
pump command status will not be ef-
fected by this diagnostic in either case.
Local
Evaporator Water
Flow Overdue –
Pump 1
Chiller
Warning
and Special
Action
NonLatch
All
After the pump request was activated,
-
tablished. Special action is to keep the
evap pump request active in a diagnos-
tic override mode.
Local
Evaporator Water
Flow Overdue –
Pump 2
Chiller
Warning
and Special
Action
NonLatch
All
After the pump request was activated,
-
tablished. Special action is to keep the
evap pump request active in a diagnos-
tic override mode.
Local
Evaporator Water
Flow Lost
Chiller
Immediate
NonLatch
[All Stop modes]
a.
input was open for more than 6 con-
tiguous seconds (or 20 seconds for
b. This diagnostic does not de-energize
the evap pump output.
c.
clear this diagnostic.
Local
Evaporator Water
Flow Lost – Pump 1
Chiller
Warning
and Special
Action
NonLatch
All
only. Evaporator Water Flow Lost diag-
nostic occurred while Pump 1 was the
selected pump.
Local
Controls
88
RTAG-SVX001H-EN