A421 Series Electronic Temperature Controls
with Cycle Timer 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 can
be set up to restrict user adjustments. An LED indicates
the output relay's on and off status.
A421 Control with Cycle Timer also provides sensor
offset capability and restricted user adjustment. 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).
The control housing base on the Type 4X/IP66 models can
be easily rotated 180º relative to the control housing cover
and LCD, allowing you to bring the electrical connection to
either the top or bottom of the mounted control. Do not
twist the wiring harness between the housing base and
cover more than 180º.
Dimensions
Figure 1: A421ABT Control with Type 1 (NEMA), IP20
enclosure; dimensions, in. (mm)
Figure 2: A421AET Control with Type 4X (NEMA), IP66
enclosure; dimensions, in. (mm)
Part No. 24-7664-3043 Rev. C
2018-11-13
A421ABT, A421AET
