Relay status LED - PENN Controls - A421ABG - A421ABJ - A421AEJ - Electronic Temperature Control - A421 Standard Model

A421 Series Standard Electronic Temperature Controls with Power Cords Installation Guide

Product name
A421 Standard Model
Document type
Installation Guide
Document revision
Revision date

The green LED on the front panel illuminates when the SPDT output relay is energized. See Figure 1.

  • LED On = Output Relay energized and the LC contact is closed to the LNO contact
  • LED Off = Output Relay de-energized and the LC contact is open to the LNO contact
Table 1. Standard parameter setup codes, descriptions, range of values, and default values
Parameter code Parameter description (menu) Range of usable values Factory default value 1
Un Temperature Units (Advanced only) ºF or ºC ºF
OFF Relay Off Temperature (Basic, Advanced, and Restricted)

-40ºF to 212ºF

(-40ºC to 100ºC)

On Relay On Temperature (Basic and Advanced)

-40ºF to 212ºF

(-40ºC to 100ºC)

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)

So Sensor Offset Adjustment (Advanced only)

-5ºF to 5ºF

(-3ºC to 3ºC)

HtS High Temperature Stop (Advanced only)

-40ºF to 212ºF

(-40ºC to 100ºC)

LtS Low Temperature Stop (Advanced only)

-40ºF to 212ºF

(-40ºC to 100ºC)

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)
1 The default values for general application A421 models are shown. OEM A421 models may have different default values.