6©Copyright 2008 TAC All Rights Reserved. F-24577-3
Switching Adjustment
The 2214 series thermostats are factory calibrated to switch
from day to night action at a pressure between 17 and
21 psig. If necessary, adjust the switch point as follows:
Note:
•The switch point adjustment should be made on a test
bench at which a variable main air supply is available.
•It is necessary to read the branch line pressure while
making the switch point adjustment.
1. Set the main air supply to the thermostat to the desired
switch over point. For example, if system pressure is
13 psig day and 18 psig night, the desired switch over
point would be between 15 and 16 psig.
2. Position the day and night setpoints according to
Table-5.
3. Verify that the branch line pressure gauge or branch
pressure tap reads approximately the main air pressure
being fed to the thermostat. If not, recheck the day
setpoint calibration.
4. To lower the switch over point, use a 20-881 thermostat
wrench (1/16” hex wrench) to turn the switching screw
clockwise, 1/8 turn at a time, until the branch line
pressure falls. To raise the switch over point, turn the
switching screw counterclockwise in the same manner.
Caution:
Do not force the calibrating screws. If the desired
action is not obtained when the screws are rotated, check to
be sure the direction of rotation is correct.
5. Lower the main air pressure to the desired system day
pressure and observe the branch line pressure. The
branch line pressure should rise to approximately the
main air pressure.
6. Raise the main air pressure to the night setting and
observe the thermostat for proper function. As the main
air pressure rises past the switch over point, the branch
line pressure should drop off to zero. Lower the main air
pressure and verify that the branch line pressure rises
from zero as the main air pressure drops below the
switch over point.
7. Reinstall the thermostat cover and recheck the
calibration at both day and night settings.
Table-5 Day and Night Setpoints.
Thermostat Model Day Night
2214-121, 2214-131, 2214-521, 2214-621 55 °F 80 °F
2214-122, 2214-132, 2214-522, 2214-622 85 °F 50 °F
Internal Stop Kit (Accessory)
The internal stop kit, model 20-712, consists of two screws
and two nuts (Figure-9). Install this kit as follows:
1. Move the setpoint adjustment to one extreme limit.
2. Place a nut in the depression in the top plate and move
the adjustment cam overthenut, to where the slot in the
cam exposes the threads of the nut.
3. Thread a stop screw into the nut far enough to allow the
stop to slide in the slot. Repeat on the other side.
4. Move the setpoint adjustment to the desired
temperature, using the internal setpoint indicator.
5. Slide the stops to the desired limits and tighten both
screws.
MAINTENANCE
The thermostat requires no maintenance.
Regular maintenance of the totalsystem is recommended to
assure sustained, optimum performance.
FIELD REPAIR
None. Replace an inoperative thermostat with a functional
unit.
DIMENSIONAL DATA
1-1/4
(3.18) 1-3/8
(3.5)
1/8
(.318)
1-3/8
(3.5) 2-1/32
(5.16)
2-1/32
(5.16)
MB
Dimensions are in inches (mm).
Figure-10 Mounting Dimensions.
