Honeywell AT140A, AT175A, AT150A, AT120A User Manual

AT120A, AT140A, AT150A, AT175A Universal Transformers
INSTALLATION INSTRUCTIONS

APPLICATION

These transformers are for use in 24 Vac nominal control circuits. They are typically used in heating/cooling control systems but can be used in any application that does not exceed the load ratings. They meet National Electrical
Table 1. Model Specifications.
Primary Secondary
Model
Number
AT120A 120/208/
AT140A 120 9 in. leads 27.0 24.0 Screw
AT150A 120/208/
AT175A 120/208/
Input
Vol tag e
(60 Hz)
240
120/208/ 240
120/240
208/240
240
240
Wiring
Connections
9 in. leads 27.0 24.0 Screw
9 in. leads 27.5 24.0 Screw
9 in. leads 27.5 24.0 Screw
Open
Circuit
Code Class 2 “not wet” and Class 3 “wet” requirements and are Underwriters Laboratories (UL) Inc. listed under UL 1585. They can be mounted through a 7/8 in. knock­out on the accessory mounting plate (included), or with the integral mounting feet. See Table 1 for additional specifications.
Vol tag e
At Rated
Power
Output
Wiring
connections
terminals
terminals
terminals
terminals
Output Rating at
100 Percent Power
20 VA
40 VA
50 VA
75 VA
Factor

INSTALLATION

When Installing this Product …

1. Read these instructions carefully. Failure to follow them could damage the product or cause a hazard­ous condition.
2. Check the ratings given in the instructions and on the product to make sure the product is suitable for your application.
3. Installer must be a trained, experienced service technician.
4. After installation is complete, check out product operation as provided in these instructions.
CAUTION
Electrical Hazard. Can cause electrical shock or equipment damage.
Disconnect power supply before beginning installation.
69-0251-3
AT120A, AT140A, AT150A, AT175A UNIVERSAL TRANSFORMERS

Mounting

The transformer can be mounted in one of three ways: — foot mounting. — plate mounting. — mounting through outlet box knockout hole.
Foot Mounting
1. Mount the transformer using screws (not supplied) through the four 3/16 in. x 3/8 in. holes in the mounting feet.
2. Make line voltage primary connections within an approved enclosure. See Fig. 1.
3. Discard the mounting plate.
USE SCREWS OR BOLTS THROUGH SLOTS (4) IN MOUNTING FEET
LEADWIRES FOR PRIMARY CONNECTIONS
SCREW TERMINALS FOR SECONDARY CONNECTIONS
LEADWIRES FOR PRIMARY CONNECTIONS
CLAMP SCREW AND CLAMP
LEADWIRES FOR PRIMARY CONNECTIONS
PLATE MOUNTED AT CLAMP ON PRIMARY END BELL
MOUNTING PLATE
SCREW
END BELL
RAISED PORTION OF LARGE CENTER KNOCKOUT
TERMINALS FOR SECONDARY CONNECTIONS
PLATE MOUNTED AT THE LAMINATIONS
MOUNTING PLATE
MOUNTING SCREW
SCREW TERMINALS FOR SECONDARY CONNECTIONS
1
MOUNTING FOOT (2)
M9161
Fig. 1. Foot mounting.
Plate Mounting
MOUNTING PLATE TO TRANSFORMER
Mount the plate to the transformer in either of two positions (see Fig. 2):
• at clamp on primary end bell.
• at laminations.
69-0251-3 2
1
1
MOUNTING FEET ON "A" MODELS ONLY.
Fig. 2. Mounting plate to transformer in either
of two positions.
MOUNTING PLATE AT CLAMP ON PRIMARY END BELL
1. Turn the screw on the clamp almost all the way out.
2. Hold the mounting plate with the keyhole slots up
and the raised portion of the large center knockout away from you.
3. From the back, thread the primary leadwires through the round center hole in the plate.
4. Fit the clamp and screw through the round hole.
5. While holding the plate in place, tighten the
setscrew securely against the rim of the hole. See Fig. 3. Avoid damaging the leadwires with the screwdriver.
M9162
Loading...
+ 2 hidden pages