Carrier 37HS Series, Installation Instructions Manual

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VARIABLE AIR VOLUME CONTROLS — 37HS4 UNIT
From the universal control package, select the following com-
ponents (see Fig. 21):
• filter assembly
• pneumatic tubing,
11 ⁄
16
in. long
• volume controller
• diffuser baffle, wide, 3
5 ⁄
8
in. long
• thermostat/aspirator assembly
• thermostat lever, no. 37AH501182
• clear plastic tube, 5
3 ⁄
4
in. long
• white foam thermostat gasket
• 2-in. offset rubber tube
• brass tee
• thermostat mount spring clip
Control Installation, 37HS4 Unit
1. Remove the plugs from the high-pressure and low-
pressure ports located at the control block of the unit.
2. Remove cap from bellows fitting and install 11 ⁄
16
-in. long
piece of 1 ⁄
4
-in. OD pneumatic adapter tubing onto the
bellows fitting (push on full length of fitting). See Fig. 22.
3. Push the diffuser baffle into the space between side dif-
fusers and down onto the center diffuser at the end away
from the unit. Then push down the end close to the unit.
The baffle will form around the legs of the diffuser spacer
and lock onto the center diffuser. See Fig. 23. Baffle should
fill space between side diffusers between unit end and
thermostat.
4. To prepare the control filter for installation, be sure that
the bellows chamber filter plug is pushed tightly into
the correct connection. Figure 24 shows the connection
ports on both sides of the filter. The lower bellows port
on the unit side and the small bellows pressure connec-
tion on the control side should be capped or plugged
before installation.
5. Moisten the 2 O-rings with water, then push the filter
into the unit control block and onto bellows connection
until the standoffs rest on the unit end plate.
120
100
80
40
CFM
%
Fig. 21 — Components Selected From
Universal Control Package for
Installation on 37HS4
BELLOWS
FITTING
FOR
DIFFUSER
THERMOSTAT
ASPIRATOR
HIGH
LOW
Fig. 22 — Typical 37HS Air Terminal
Before Installation of Controls
Fig. 23 — Diffuser Baffle Assembly
Fig. 24 — Filter/Manifold Connections
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