Enertech Global, LLC
23
WS Rev. E Models
Installation and Operations Manual
Temperature vs Resistance Characteristics of Sensor
Temp. (°F)
Rst. (KΩ)
Temp. (°F)
Rst. (KΩ)
10
46.95
130
3.60
15
41.39
200
1.16
20
36.50
220
0.87
30
28.61
250
0.59
77
10.00
257
0.54
Over/Under Voltage Protection
The lockout board protects the compressor from operating
when an over/under voltage condition exists. The control
monitors secondary voltage (24VAC) to determine an over/
under voltage condition is occurring on the primary side of
the transformer. For example, if the secondary voltage is
18VAC, the primary voltage for a 240V unit would be
approximately 180V which is below the minimum voltage
(197V) recommended by the compressor manufacturer.
Under voltage (<18VAC) causes the compressor to disengage
and restart when the voltage returns to >20VAC. Over voltage
(>31VAC) causes the compressor to disengage and restart
when the voltage returns to <29VAC.
When an O/U Voltage condition occurs, the board will initiate
a fault, shut down the compressor, and start the five minute
ASC period. All four fault LEDs will flash (HP + LP + FS + CO)
and the thermostat “Call For Service” indicator will be
illuminated. This feature is self-resetting and never retries or
locks out. If voltage returns to normal range normal operation
will resume if/when the ASC period is over. When normal
operation is restored the four fault LED’s will stop flashing
and the “Call For Service” indicator will turn off.
Fault Retry
All faults (except O/U Voltage) are retried twice before finally
locking the unit out. The fault retry feature is designed to
prevent nuisance service calls. There is an anti-short cycle
(ASC) period (5 min.) between fault retries. On the third fault
within 30 minutes, the board will go into lockout mode and
the “Call For Service” indicator on the thermostat will
illuminate.
Intelligent Lockout Reset
If the thermostat is powered off for one minute then back on
(soft reset), the board will reset and the last fault will be
stored in memory for ease of troubleshooting. If power is
interrupted to the board, the fault memory will be cleared.
Lockout with Emergency Heat
While in lockout mode, if the thermostat is calling for
auxiliary heat (W1), emergency heat mode will energize. W2
is energized two minutes after W1 is energized.
Hot Water Generator (HWG) Pump Control (If
equipped with Desuperheater)
Controls check for HWG temperature (T3) and hot gas
(compressor discharge) line (HGT) temperature (T2). The hot
water generator pump is de-energized when the leaving
water temperature (T3) is above 130°F or when the
compressor discharge line (T2) is cooler than leaving water
temperature (T3). Also when the hot gas line temperature
(T2) is higher than 220°F, the HWG pump will be de-
energized. All of the issues above will break the circuit of the
HWG pump (via the HWG signal from the lockout board) and
will not lockout the compressor except when T2>220°F. Units
without a HWG also do not have sensors T2 and T3. The
control ignores T2 and T3 and disables Faults 15 and 16,
Sensor BAD.
Temperature Sensor Operating Range
Sensor’s Name
R
ange(°F)
T1
10 – 220
T2
20 – 257
T3
20 – 220
T4
10 – 220
Load Heat Exchanger Freeze-T1 (If equipped - units with
coaxial heat exchangers):
When in cooling mode, if the heat
exchanger temperature is lower than 30°F for 30 continuous
seconds, the compressor operation will be interrupted, and
the control will go into fault retry mode. This sensor is located
on the refrigerant line in between the heat exchanger and
TXV (refrigerant inlet of heat exchanger in cooling mode).
Source Heat Exchanger Freeze -T4 (If equipped - units with
coaxial heat exchangers):
When in heating mode, if the heat
exchanger is lower than setpoint for 30 continuous seconds,
the compressor operation will be interrupted, and the control
will go into fault retry mode. The setpoint is 12°F for closed
loop (A-FRZ jumper removed) and 30°F (A-FRZ jumper
installed) for open loop. At startup, the flow sensor is not
monitored for 30 seconds to avoid nuisance faults. This
sensor is located on the refrigerant line in between the
source heat exchanger and TXV (refrigerant inlet of heat
exchanger in heating mode).
Hot Gas Line Temperature limit (T2>220°F):
When T2 is
>220°F for 30 continuous seconds, the compressor operation
will be interrupted. The control will go into fault retry mode.
Section 8: Controls
Over/Under Voltage Protection
The lockout board protects the compressor from operating
when an over/under voltage condition exists. The control
monitors secondary voltage (24VAC) to determine an over/
under voltage condition is occurring on the primary side of
the transformer. For example, if the secondary voltage is
18VAC, the primary voltage for a 240V unit would be
approximately 180V which is below the minimum voltage
(197V) recommended by the compressor manufacturer.
Under voltage (<18VAC) causes the compressor to disengage
and restart when the voltage returns to >20VAC. Over voltage
(>31VAC) causes the compressor to disengage and restart
when the voltage returns to <29VAC.
When an O/U Voltage condition occurs, the board will initiate
a fault, shut down the compressor, and start the five minute
ASC period. All four fault LEDs will flash (HP + LP + FS + CO)
and the thermostat “Call For Service” indicator will be
illuminated. This feature is self-resetting and never retries or
locks out. If voltage returns to normal range normal operation
will resume if/when the ASC period is over. When normal
operation is restored the four fault LED’s will stop flashing
and the “Call For Service” indicator will turn off.