FORM 155.21-O1 (615)
55
JOHNSON CONTROLS
2
Low Ref Temp in Evap RT8 < 34.0°F (1.1°C) -
Soln Pump is off
The evaporator refrigerant temperature is less than
or equal to 34°F (1.1
°C)
.
When this warning occurs the unit stops the solu-
tion pump, opens 2SOL if the refrigerant pump is
running, inhibits load command for valve opening,
and closes alarm contacts.
Recovery Condition
• Refrigerant temperature is greater than 34°F
(1.1°C)
; changes warning message to "LOW RE
-
FRIGERANT TEMPERATURE RT8
is less than
35.5°F (1.9°C)", this message allows the solution
pump operation.
• Refrigerant temperature is greater than 36°F
(2.2°C)
; it releases the warning, closes 2SOL,
enables the solution pump operation and LOAD
command for the control valve. It is required to press
the WARNING RESET key when in OPERATOR
or SERVICE access to clear this message.
• Pressing the WARNING RESET key at any
moment opens the alarm contacts.
Low Refrigerant Temperature in Evap RT8 <
35.5°F (1.9°C)
The evaporator refrigerant temperature is less than
or equal to 35.5°F (1.9°C).
When this condition occurs the unit opens 2SOL if
the refrigerant pump is running, inhibits load com-
mand for valve opening, and will close the alarm
contacts.
Recovery Condition
• Refrigerant temperature is greater than 36°F
(2.2°C)
; it releases this warning, closes 2SOL,
enables the solution pump operation and LOAD
command for the control valve. It is required to press
the WARNING RESET key when in OPERATOR
or SERVICE access to clear this message.
•
Pressing the WARNING RESET key at any
moment opens the alarm contacts.
Possible Crystallization RT2 > 160ºF (71.1ºC)
Temperature on the automatic decrystallization line
(RT2) exceeded 160 ºF (71.1ºC) during operation. Au
-
tomatic decrystallization process started.
Recovery Condition
• Temperature on the automatic decrystallization line
(RT2) decreased below 150 ºF (65ºC) when the ADC
process timed out.
Purge Failure; PT3 > 15mmHg -
Check Purge Pump
This message occurs when the unit is attempting to
perform a manual or auto purge, the purge pump is run-
ning and the purge pump pressure does not decrease
less than 15mmHg within 2 minutes from 8SOL re
-
ceiving an open command. The unit will close 8SOL,
stop the purge pump, after 65 seconds change the pump
mode to MANUAL, and close the alarm contacts. The
unit performs a safety check corresponding to the cur-
rent operation state.
Recovery Conditions
• Press the WARNING RESET key in OPERATOR
or SERVICE access to clear the warning.
• Pressing the WARNING RESET key at any moment
opens the alarm contacts.
Purge Pump failure - manually close VP2 & VP4
This message occurs when the purge pump pressure at
PT3 is greater than 100mmHg and the purge pump is
running. The unit will close 7SOL and 8SOL if open,
turn OFF the purge pump after 65 seconds, change the
purge mode to MANUAL if in AUTO, and close the
alarm contacts.
Recovery Condition
• Purge pump pressure is less than 100mmHg; it
releases this warning but it is required to press the
RESET WARNING key in OPERATOR or SER
-
VICE access to clear the warning.