Lennox CLIMATIC II User Manual

V2.2
-00
9
CONTROL OF COMPRESSORS
Function
The compressors are started up and stopped in the order which avoids the anti-short cycle, as far as possible,
and evens out their operating times..
Description
F Start-up and stopping order for compressors
This order is determined by a “FIFO” (first in, first out) rule. This function incorporates the automatic,
instantaneous recording of a priority compressor which has become unavailable
F Compressor start-up and stopping
The compressor COMPmn starts up if all the following conditions are satisfied :
ð The water circulation pump received the order to operate at least 1 minute earlier.
ð The on / off switch for circuit n is ON (MAARn = 1).
ð The machine is available (DISPOM = 1).
ð Circuit n is available (DISPOCn = 1).
ð Compressor mn is available (DISPOmn = 1).
ð The regulation thermostat THER is greater than the number of compressors in service.
ð COMPmn is the compressor defined by the FIFO rule as the next one to start up.
ð COMPmn is not in anti-short cycle (ACCmn = 1).
The compressor COMPmn stops if at least one of the following conditions is satisfied :
ð The remote on / off switch for the machine is OFF (MAARD = 0).
ð The on / off switch for circuit n is OFF (MAARn = 0).
ð The machine is unavailable (DISPOM = 0).
ð Circuit n is unavailable (DISPOCn = 0).
ð Compressor mn is unavailable (DISPOmn = 0).
ð The regulation thermostat THER is less than the number of compressors in service and COMPmn is the
compressor defined by the FIFO rule as the next one to be stopped.
F Example of regulation with 4 compressors :
THER
0 1 2 3 4 3 4 3 2 1 2 3 2 3 4 3 2 1 0
Last one started up
- 1 2 3 4 - 1 - - - 2 3 - 4 1 - - - -
Last one stopped
- - - - - 1 - 2 3 4 - - 1 - - 2 3 4 1
Compressor
number
In operation
- 1 1 2
1 2
3
1 2
3 4
2
3
4
2 3
4 1
3 4
1
4 1 1 1 2
1 2
3
2 3
2 3
4
2 3
4 1
3 4
1
4 1 1 -

Lennox CLIMATIC II Specifications

General

Category	Control Unit
Model	CLIMATIC II
Compatibility	Lennox HVAC Systems
Type	Thermostat
Temperature Increment	1°F
Mounting	Wall Mount

Summary

CONTROL AND REGULATION

CONTROL OF EVAPORATOR PUMPS

COLD THERMOSTAT

HOT THERMOSTAT

CONTROL OF COMPRESSORS

Manages compressor start-up and stop to avoid anti-short cycle.

CONTROL OF ELECTRONIC EXPANSION VALVE

Controls evaporator filling for efficiency and compressor protection.

CONTROL OF CONDENSER FANS

OPTIONS

FREE-COOLING

Ensures refrigeration while optimizing free-cooling and limiting consumption.

HEAT RECOVERY

MANAGEMENT OF UNITS IN PARALLEL

Stages units to adjust cooled fluid temp precisely.

MACHINE FAULTS

TEMPERATURES OF CHILLED WATER OUTSIDE RANGE

Input/output chilled water temp sensor outside authorized range.

HOT WATER TEMPERATURES OUTSIDE RANGE

INSUFFICIENT FLOW OF CHILLED WATER

Flow switch detects insufficient flow in evaporator for over 2 seconds.

INSUFFICIENT FLOW OF HOT WATER

Flow switch detects insufficient flow in condenser for over 3 seconds.

ABSENCE OF 230V SUPPLY WITH BACKUP

INCORRECT SEQUENCE OF PHASES

Phase controller tripped, detects inversion or bad phase coupling.

CIRCUITS FAULTS

LOW PRESSURE INSUFFICIENT

Low pressure remains lower than safety limits on circuit n.

EVAPORATOR FREEZING

Evaporation temperature too low, risking freezing.

INSUFFICIENT SUPERHEATING

Superheat level is insufficient for proper operation.

VACUUM SUCCION FAILURE

SENSOR OR DETECTOR FAULTS

EXPANSION VALVE OPENING INCORRECT

Expansion valve opening not reached during pre-heat phase.

COMPRESSOR FAULTS

COMPRESSOR CUT-OUT SWITCH TRIPPED

Thermomagnetic cut-out switch on compressor tripped.

OIL PRESSURE INSUFFICIENT

Oil pressure insufficient for proper compressor lubrication.

EXCESS HIGH TEMPERATURE

High pressure safety cut-out on compressor tripped.

DISCHARGE TEMPERATURE TOO HIGH

Discharge temperature on compressor stays over 120°C.

INTERNAL PROTECTION TRIPPED

Thermal protection on motor windings tripped.

MISCELLANEOUS FAULTS

INSUFFICIENT FLOW ESTABLISHED BY THE PUMP

FANS CIRCUIT BREAKERS TRIPPED

PUMP CIRCUIT BREAKER TRIPPED