Penn A421ABD-02C - User Manual

A421 Series Electronic Temperature
Controls with Off-Cycle Defrost Installation
Guide
Applications
Important: Use this A421 Series Electronic Temperature Control only as an operating control.
Where failure or malfunction of the A421 Control could lead to personal injury or property
damage to the controlled equipment or other property, additional precautions must be
designed into the control system. Incorporate and maintain other devices, such as supervisory
or alarm systems or safety or limit controls, intended to warn of or protect against failure or
malfunction of the A421 Control.
Important: Utiliser ce A421 Series Electronic Temperature Control uniquement en tant que
dispositif de régulation. Lorsqu'une défaillance ou un dysfonctionnement du A421 Control
risque de provoquer des blessures ou d'endommager l'équipement contrôlé ou un autre
équipement, la conception du système de contrôle doit intégrer des dispositifs de protection
supplémentaires. Veiller dans ce cas à intégrer de façon permanente d'autres dispositifs,
tels que des systèmes de supervision ou d'alarme, ou des dispositifs de sécurité ou de
limitation, ayant une fonction d'avertissement ou de protection en cas de défaillance ou de
dysfonctionnement du A421 Control.
The A421 Series Electronic Temperature Controls are single-stage, electronic temperature controls
with a single-pole, double-throw (SPDT) output relay.
A421 Controls feature a backlit LCD with adjustable brightness and three-button touchpad interface
that you can set up to restrict user adjustments. An LED indicates the output relay's on/off status.
A421 Controls have simple on and off temperature settings for heating or cooling, an adjustable
anti-short cycle delay, temperature setback, and sensor offset capability. The temperature control
range is -40°F to 212°F or -40°C to 100°C.
The A421 Controls are available either in Type 1 (NEMA), IP20 (CE), high-impact plastic enclosures
suitable for surface or DIN rail mounting (Figure 1), or in Type 4X (NEMA), IP66 (CE) watertight,
corrosion resistant surface mount enclosures (Figure 2).
Part No. 24-7664-3035 Rev D
2018-11-13
A421ABD-x, A421AED-x

Penn A421ABD-02C Specifications

General

Brand	Penn
Model	A421ABD-02C
Category	Control Unit
Language	English

Summary

Mounting Instructions

Wiring the A421 Control

TB2 Terminal Block and SPDT Relay

Wiring Terminals and Wire Sizes

Details terminal block functions, requirements, and recommended wire sizes.

Control Setup and Parameters

Key Parameter Settings

Defrost Cycle Configuration

Navigating Control Menus

Basic and Advanced Menu Navigation

Instructions on how to navigate the Basic and Advanced setup menus.

Parameter Adjustment Procedures

Defrost Operation Modes

Timed Defrost Cycle Setup

Explains how to set up regular timed defrost cycles using dI and dFt parameters.

Manual Defrost Control Methods

Describes how to manually start or stop a defrost cycle using SdF or binary input.

Restricting User Adjustments

Enabling Restricted Adjustment Mode

Adjusting Parameters in Restricted Mode

Troubleshooting and Repair

Understanding Fault Codes

Troubleshooting Procedures

Step-by-step guide to diagnose and resolve control issues.