Setting up a regular or timed Defrost Off-Cycle - PENN Controls - A421ABD - A421AED - Electronic Temperature Control - A421 Off‐Cycle Defrost Model

A421 Series Electronic Temperature Controls with Off-Cycle Defrost Installation Guide

Product name
A421 Off‐Cycle Defrost Model
Document type
Installation Guide
Document revision
Revision date

The following behavior is enforced:

  • At power up, the initial Defrost Interval (dI) does not have a Defrost Cycle (dFt).
  • Subsequent defrost intervals (dI) begin with the selected dFt value.
  • All defrost intervals have the same length.

To set up a regular or timed defrost cycle:

  1. Select a dI value between 2 hours and 24 hours.
    Note: A dI value of 0 indicates no defrost interval.
  2. Select a dFt value between 1 minute and 99 minutes. See Figure 1.
    Figure 1. Typical passive Defrost Cycle behavior