Carrier 37HS Series, Installation Instructions Manual, Page: 8 / 12

11. Moisten the O-rings of the volume controller with water
and push the controller directly into the filter.
12. Install the thermostat on the center diffuser, then snap
spring clip over thermostat and onto the side diffusers to
hold thermostat in place. See Fig. 30. Make sure that
thermostat lever will rotate.
13. Remove cap from the aspirator supply port on the unit
control block. Connect the clear, 5 3 ⁄
4
-in. long aspirator
supply tube to the control block connection. Figure 30
shows the completed installation.
The brass tee is used for slave unit connection where
3 or more units are used in air series. See Interconnect-
ing Tubing, All Models, on this page.
INTERCONNECTING TUBING, ALL MODELS See Fig. 31.
For 2 units controlled by a single volume controller —
1. Use
1 ⁄
4
-in. OD FR tubing. Connect tubing to the unit bel-
lows connection on end of the master unit opposite the
control end. Do not connect tubing to capped filter bel-
lows connection.
2. Connect tubing to slave unit.
For 3 or more units controlled by a single volume controller —
1. Using brass tee, connect
1
⁄
4
-in. OD FR tubing from the
master unit to the 2 slave units on each side of the master
unit.
2. Attach interconnecting tubing from these 2 slave units in
the air series.
AIR FILTER
ASPIRATOR
THERMOSTAT
SPRING
CLIP
VOLUME CONTROLLER
Fig. 30 — 37HS4 VAV Control Installation
FR — Fire Retardant
Fig. 31 — Control Arrangements — Master Units with Slaves
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