2A28PA and A28PJ Series Two-Stage Temperature Controls with Type 4X Raintight Enclosures Installation Guide
Mounting
Mount the temperature control in a location that
exposes it to the average temperature of the controlled
space. Do not mount the control where unusual heat
or cold can affect it, such as over an animal stall or in
direct sunlight. Avoid locations near doors, windows,
or other sources of non-ambient air drafts. Do not
mount the control on an outside wall or where the
temperature at the sensing element exceeds 140°F
(60°C).
Mount the temperature control to a flat surface with
screws through the holes in the mounting tabs on the
back of the case.
Wiring
WARNING: Risk of Electric Shock.
Disconnect or isolate all power supplies before
making electrical connections. More than one
disconnection or isolation may be required to
completely de-energize equipment. Contact with
components carrying hazardous voltage can cause
electric shock and may result in severe personal
injury or death.
ADVERTISSEMENT : Risque de décharge
électrique.
Débrancher ou isoler toute alimentation avant de
réaliser un branchement électrique. Plusieurs
isolations et débranchements sont peut-être
nécessaires pour -couper entièrement l'alimentation
de l'équipement. Tout contact avec des composants
conducteurs de tensions dangereuses risque
d'entraîner une décharge électrique et de provoquer
des blessures graves, voire mortelles.
Important:All wiring must conform to all local,
national, and regional regulations. Use copper
conductors only for all wire connections.
Important: Do not use A28 temperature controls on
applications where the electrical load across the
control’s switch may exceed the electrical ratings
shown on the temperature control’s label.
Important: Use only the terminal screws furnished
with the switch. Using other screws in the switch
voids the warranty, may damage the switch, and
may cause problems in making secure connections.
The wiring terminals of each switch are color coded to
simplify wiring. Red (R) is the common terminal. The
red to yellow (Y) circuit closes on temperature
increase. In standard applications, you can wire from
R to Y to control cooling or ventilating equipment. The
red to blue (B) circuit opens on temperature increase.
In standard applications you can wire from R to B to
control heating equipment.
To make wiring connections, complete the following
steps:
1. Loosen the four cover screws and remove the
cover and knob assembly. Do not remove the
knob, it is secured in the cover. Do not damage
the O-ring.
2. Select the knockout that you want to remove.
3. Place a screwdriver blade on the knockout near
the edge.
4. Apply a sharp blow to the screwdriver handle to
loosen the knockout.
5. Connect an approved watertight conduit fitting to
the conduit.
6. Connect the fitting to the A28PA or the
A28PJ control enclosure.
Note: For flexible conduits, you can reverse Step
5 and Step 6.
7. Insert the wire through the conduit opening.
8. Make the wiring connections to the screw
terminals. See Figure 2, Figure 3, and Figure 4.
9. Ensure that the enclosure O-ring is securely
seated in the groove so that it forms a correct seal
between the cover and case.
10. Replace the cover and knob assembly.
11. Check the alignment of the range adjustment
knob.
Dial
R
B
Y
R
B
Y
A28 Temperature
Control
Low and High Temperature
Stage Switch-Action is:
closes and opens
on temperature decrease.
R to B R to Y
R to Y R to Bcloses and opens
on temperature increase.
Low Temp.
Stage
High Temp.
Stage
996545_2.cdr
Figure 2: A28 temperature control switch action
