Direct-mounting a Type 1/IP20 control to a wall or other flat surface using the four keyhole slots - PENN Controls - A421ABG - A421ABJ - A421AEJ - Electronic Temperature Control - A421 Standard Model

A421 Series Standard Electronic Temperature Controls with Power Cords Installation Guide

PENN Controls
Product name
A421 Standard Model
Document type
Installation Guide
Part number
Document revision
Revision date


  1. Disconnect the power and remove the enclosure cover. Place the control horizontally against the wall surface in a suitable location, and mark the keyhole slot locations on the mounting surface.
  2. Install appropriate screws or fasteners and leave the screw heads approximately one or two turns away from flush to the mounting surface.
  3. Position the control mounting slots over the screw heads, and then tighten the mounting screws to secure the control to the surface.
    Note: When you mount the control on an uneven surface, use shims to mount the control evenly.