Thermostat Function - Foster FTG3.5-5 Technical Manual

MICROPROCESSOR CONTROLS
Duet 'M' and 'L' Series
All controller parameters are factory set for optimum storage conditions.
The parameters should only be adjusted by persons familiar with the
unit operation and controller functions. Certain parameters however
may be adjusted within limits, to suit certain storage needs.
5 6
1
2
CDC 122
Check Set Point — Low point of temperature band
Press button 1
Increase Set Point
Press and hold button 1
Press button 3 until required temperature is displayed
Decrease set point
Press and hold button 1
Press button 4 until required temperature is displayed
Manual Defrost
Press and hold button 2
Press button 4 a timed defrost will follow
Indicators
LED 5 Compressor on
LED 6 Evaporator fan on
LED 7 Defrost on
PF1 or PF2: Indicates a probe failure — call engineer
Adjustment Parameters
Freezer: Set Point -21°C
Meat: Set Point -2°C

Thermostat Function

SPL Min set point (°C)
Maximum allowable low alarm setting (°C)
SPh Maximum set point (°C)
Maximum allowable high alarm setting (°C)
hyS
Temperature hysteresis (°K)
coF Compressor minimum off time (mins)
con Compressor minimum on time (mins)
cdc Cooler duty cycle. Compressor on duration during a ten minute
cycle e,g. cdc = 04, 4 min on time, 6 min off time (active only
under probe fault conditions, PF1)
crS Compressor start delay (secs)
Defrost Function
drE Time between defrosts (hrs)
dLi
Defrost termination temperature (°C)
dto
Defrost termination time (mins). Unused if set to zero
7
drP Drain down time (mins)
diS Display during defrost
00 = Temperature display
— 01 = DEF is displayed during defrost and until air
1.30 (mins) = dEF is displayed during defrost and until the
set
dtY Defrost type
FAn = Off cycle defrost
3
ELE = Electric heater defrost
GAS = Hot gas defrost
4
doP Defrost optimisation
con = At regular intervals of drE (hrs)
Acc
= Defrost timer only runs while evaporator
temperature is below 0°C, defrosting occurs when drE time
has elapsed e.g. if compressor cycle time is 5 min run and 5
min stop and drE = 4, defrosting will take place every 8 hours
Evaporator Fan Control
Fct Evaporator fan control during cooling
— 01 = Continuous operation
00 = Cycle on/off with compressor
1.10 (mins) = Start with compressor, set time delay stop
Frs
Fan delay temperature following defrost (°C)
Fid Evaporator fan operation during defrost
00 = off until fan delay temperature FrS (°C)
01 = On while evaporator temperature is below
02 = On during defrost
Alarm Function
ALo
Low temperature alarm setting (°C)
Ahi High temperature alarm setting (°C)
AdL Alarm delay (min)
00 = Instantaneous audible alarm
01.120 = Duration of delay (min)
— 01 = Alarm is disabled
Ain Determines which probe is monitored for alarm functions
1 = Air probe (prode 1)
2 = Evaporator probe (probe 2)
3 = Food probe (probe 3)
Thermal Mass Simulation
oS1 Air probe offset (°K)
oS2 Evaporator probe offset (°K)
oS3 Food probe offset (°K) — where fitted
SiM Controls the thermal mass volume simulated by the controller
and displayed on the fascia. The greater the value the greater
the resulting display slow down. The controlling function
remains to operate directly on air temperature.
00 = Instantaneous air temperature display
01.200 = Thermal mass simulation
Adr Controller peripheral number — only used where controllers
are networked
9
temperature falls below the value setpoint —
hysteresis.
time has elapsed after defrosting or until air
temperature falls below the value setpoint +
hysteresis.
after compressor
is reached
value FrS (°C)