Penn A421 Series - 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

Summary

Applications

Off-Cycle Defrost Control

Mounting

Mounting a Type 1;IP20 Control on DIN Rail

Instructions for attaching the Type 1/IP20 control module to a 35 mm DIN rail.

Direct-Mounting a Type 1;IP20 Control

Additional Guidelines for Mounting Type 4 X;IP66 Controls

Wiring

TB2 Terminal Block and SPDT Relay Output

Setup and Adjustments

LCD Interface

Three-Button Touchpad

Parameter Codes and Operation Modes

Introduces parameter codes and explains how On/Off values determine heating or cooling modes.

Basic Menu

Viewing and Changing Values in the Basic Menu

Advanced Menu

Viewing and Changing Values in the Advanced Menu

Setting Up a Regular or Timed Defrost Off-Cycle

Restricting User Adjustment

Troubleshooting

Troubleshooting Procedure

Offers a step-by-step guide for diagnosing and resolving common issues with the A421 control.

Technical Specifications

Penn A421 Series Specifications