Specifications

Transformers
172 customer.honeywell.com 70-6910
AT120; AT140; AT150A,B; AT175A General Purpose Transformer
Provide power to 24 Vac circuits in heating/cooling control
systems. Intended for use in systems with predictable, uniform
loads. Can be used in any application that does not exceed the
listed ratings.
• Color-coded leadwires for primary connections and screw terminals
for secondary connections, fixed 1/4 inch (6 mm) male quick-
connects or color-coded leadwires for both primary and secondary,
are standard.
• Meet NEC Class 2 requirements.
• Meet Underwriters Laboratories Inc. Standard UL 1585 and are
identified. Class 2 not wet, Class 3 wet.
Temperature Rating: -20 F to +105 F (-29 C to +41 C)
Frequency: 60 Hz
NEMA Rating
AT175A1008 only: NEMA type E
Approvals:
Canadian Standards Association: CSA Certified: A & B models.
Underwriters Laboratories, Inc. UL Listed: A,C,F models. File #
E14881
Dimensions in inches (millimeters)
AT120A
AT150A
AT175A
AT140A
AT120B, AT140B,
AT140D, AT150B
Product Number
Electrical Ratings
Electrical Connections
(main)
Mounting
Dimensions, Approximate
Includes
Voltage
Output Primary Secondary (inch) (mm)Primary Secondary
AT120A1004 120 Vac,
208 Vac,
240 Vac
27 V.O.C. 24 Vac
at 20 VA
9 in.
leadwires
(2) screw
terminals
Foot mounted, plate
mounted on 2x4 in. or
4x4 in. outlet box, clamp
mounted using outlet
box knockout, or panel
mounted
2 7/8 in. high x
1 7/8 in. wide x
2 15/16 in. deep
73 mm high x
48 mm wide x
75 mm deep
—
AT120B1028 120 Vac 27 V.O.C. 24 Vac
at 20 VA
9 in.
leadwires
9 in. leadwires Foot-mounted 1 11/16 in. high
x 3 3/16 in. wide
x 1 3/4 in. deep
43 mm high x
81 mm wide x
75 mm deep
Metal end
bells
AT140A1000 120 Vac 27 V.O.C. 24 Vac
at 40 VA
9 in.
leadwires
(2) screw
terminals
Foot mounted, plate
mounted on 2x4 in. or
4x4 in. outlet box, clamp
mounted using outlet
box knockout, or panel
mounted
3 3/16 in. high x
2 3/8 in. wide x
3 1/8 in. deep
81 mm high x
60 mm wide x
79 mm deep
Metal end
bells
AT140A1018 120 Vac,
208 Vac,
240 Vac
27 V.O.C. 24 Vac
at 40 VA
9 in.
leadwires
(2) screw
terminals
Foot mounted, plate
mounted on 2x4 in. or
4x4 in. outlet box, clamp
mounted using outlet
box knockout, or panel
mounted
3 3/16 in. high x
2 3/8 in. wide x
3 1/8 in. deep
81 mm high x
60 mm wide x
79 mm deep
Metal end
bells
3-1/16 (78)
1-3/4
(44)
2 (51)
1-1/16
(27)
PLATE MOUNTED AT THE
LAMINATIONS (3/4 ABOVE
PLATE MOUNTING)
MOUNTING PLATE
2-1/4
(57)
2-3/8
(60)
3-7/32
82
FOOT MOUNTED
D
2-15/16 (76)
PLATE OR OUTLET BOX
MOUNTED AT CLAMP
ON END BELL (ALL
ABOVE PLATE MOUNTING)
M17509A
2-3/8
(60)
1/4
(6)
3-3/8 (86)
3-3/8
(86)
4-3/16
(106)
2
(51)
3 -1/4 (83)
5/16 (8)
1/8 (3)
1/8
(3)