Penn A421 Series User Manual

Start or Stop Defrost Cycle (SdF)
The Start/Stop Defrost Cycle parameter allows you to start a defrost cycle, when the control
is in normal (On/Off cycle) operation, or stop a defrost cycle when the defrost cycle is On.
Change to the SdF value to 1 to start a defrost cycle. Or, change the value to 0 to stop the
defrost cycle, and return to normal (On/Off cycle) operation.
Binary Input modes (bIn)
The BIN mode allows you to select how the A421 Control operates when a user-supplied
binary switch connected across BIN and COM on the TB3 terminal block is used with the
control.
Set the BIN parameter to 0 to use the temperature setback feature. Set the value to 1 and
connect a user-supplied momentary contact switch to start or stop a defrost cycle.
Table 3: Standard parameter setup codes, descriptions, range of values, and default values
Parameter
code
Parameter description (menu) Range of usable values Factory default
value
11
Un Temperature Units (Advanced only) ºF or ºC ºF
OFF Relay Off Temperature (Basic,
Advanced, and Restricted)
-40ºF to 212ºF
(-40ºC to 100ºC)
25ºF
On Relay On Temperature (Basic and
Advanced)
-40ºF to 212ºF
(-40ºC to 100ºC)
30ºF
ASd Anti-Short Cycle Delay (Basic and
Advanced)
0 minutes to 12 minutes 1 minute
tSb Temperature Setback (Advanced
only)
-50ºF to 50ºF
(-30ºC to 30ºC)
0ºF
So Sensor Offset Adjustment
(Advanced only)
-5ºF to 5ºF
(-3ºC to 3ºC)
0ºF
HtS High Temperature Stop (Advanced
only)
-40ºF to 212ºF
(-40ºC to 100ºC)
212ºF
LtS Low Temperature Stop (Advanced
only)
-40ºF to 212ºF
(-40ºC to 100ºC)
-40ºF
SF Sensor Failure Action (Basic and
Advanced)
0 = output relay de-
energized
1 = output relay
energized
1 output relay
energized
bLL LCD Backlight Brightness Level
Adjustment (Advanced only)
0 to 10; 0 = backlight off,
10 = brightest backlight
setting
10 (brightest
backlight)
dFt Defrost Cycle Time (Advanced only) 1 minutes to 99 minutes 30 minutes
dI Defrost Interval (Advanced only) 0 or 2 hours to 24 hours 8 hours
A421 Series Electronic Temperature Controls with Off-Cycle Defrost Installation Guide12

Penn A421 Series Specifications

General

Display	LED
Series	A421
Supply Voltage	24 VAC/VDC
Output Relay	SPDT
Sensor Type	Thermistor, Thermocouple
Type	Temperature Controller
Mounting	DIN rail
Input Voltage	24 VAC/VDC
Output Voltage	120/240 VAC
Operating Temperature	-40 to 158°F (-40 to 70°C)