background image

95C-10903-1 

T451, T651

Motor-Rated Precision Thermostats

PRODUCT DATA

The T651 thermostat provides direct, accurate line voltage 
control of inductively-rated heating, ventilating, or cooling
equipment used in commercial or industrial environments.

The T451 provides precision line voltage control of motor-
rated electric, gas or oil heating equipment.

APPLICATION

FEATURES

• Deluxe styling for commercial buildings.

• Industrial grade MICRO SWITCH™ mechanism 

rated 1/2 hp inductive, 5 kW resistive.

• Vertical mounting on 2” x 4” NEMA-standard 

single-gang outlet box.

• High-sensitivity, vapor-filled stainless steel dual

diaphragm sensing element.

• Engineering plastic base to isolate sensor from 

switch heat and minimize droop.

• CSA Certified, UL Listed.

• Altitude compensation.

• 44°F (7°C) “frost protection” setting for heating 

application, independent of calibration or altitude.

• Color-coded leadwire connections.

• Range stops/locking cover security features for 

public areas.  

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Setting and Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Contents

CL  4-01  •  © Honeywell Limited/Limitée 2001

Summary of Contents for T451

Page 1: ...CH mechanism rated 1 2 hp inductive 5 kW resistive Vertical mounting on 2 x 4 NEMA standard single gang outlet box High sensitivity vapor filled stainless steel dual diaphragm sensing element Engineering plastic base to isolate sensor from switch heat and minimize droop CSA Certified UL Listed Altitude compensation 44 F 7 C frost protection setting for heating application independent of calibratio...

Page 2: ...d some minor differences in performance can be expected if these conditions are changed Models T451A SPST and T451B DPST with positive off for heating only T651A SPDT for heating cooling Control Range 44 86 F 7 28 C for models T451A T651A 50 86 F 10 28 C for model T451B Sensing Element Vapor filled dual diaphragm Differential 2 F 1 C Droop 2 F mid load range Barometer Sensitivity 1 8 F wc 0 3 C kP...

Page 3: ...ay not be used as a disconnect switch 3 Leave cover on the thermostat while making wiring connections Use solderless connectors approved for the type number and gauge of wires being joined Connect as per Fig 2 for the appropriate application Fig 2 Wiring connections 4 Pre bend and push leadwires into the electrical junction box 5 Hold the thermostat base with one hand and remove the thermostat cov...

Page 4: ...removed setpoint knob clockwise by the amount of temperature error Each mark on the triangular arm represents 2 F 1 C of adjustment Snap the knob back onto the setpoint cam Fig 4 Recalibrating Thermostat Fig 5 Installing Range Stops Insert pins into temperature stop positions Security Features Range Stops 1 Set thermostat to desired setpoint Remove cover 2 Install plastic dowels supplied or purcha...

Reviews: