Honeywell T921G ユーザーズマニュアル
1
60-2242—2
J. D. • Rev. 1-94 • ©Honeywell Inc. 1994 • Form Number 60-2242—2
T921A,B,E-G Proportional
Control Thermostats
T921 Thermostats provide 3-wire, low voltage
proportional control for Series 90 (135 ohm) valve
motors, damper motors, and balancing relays in
heating or cooling system applications.
motors, damper motors, and balancing relays in
heating or cooling system applications.
■ Accessory faceplates available for horizontal mount-
ing of T921A,B,E models.
■ COOL-HEAT changeover switch in the T921B.
■ Night setback mechanism and switch in the T921E.
■ A spdt (single pole double throw) Class 2 auxiliary
switch in the T921F,G, which operates at the low
(T921F) and high (T921G) end of the throttling
range.
(T921F) and high (T921G) end of the throttling
range.
■ A bellows element adjusts the potentiometer slider
to regulate motor operation.
■ Various temperature ranges are available.
■ All models are available with a thermometer and a
locking cover.
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T921A
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T921B
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T921E
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T921F
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T921G
CONTENTS
Specifications ................................................. 2
Ordering Information ..................................... 2
Installation ..................................................... 4
Setting and Adjusting ..................................... 7
Operation ....................................................... 7
Ordering Information ..................................... 2
Installation ..................................................... 4
Setting and Adjusting ..................................... 7
Operation ....................................................... 7