19
INSTALLATION
Condensate Drain —
Install a trapped condensate drain
line at unit drain connection. All 39S units have a
3
/
4
in. FPT
condensate drain connection.
Measure maximum design negative static pressure up-
stream from the fan. Referring to Fig. 16, height “H” must be
equal to or larger than negative static pressure at design operat-
ing conditions. Prime enough water in trap to prevent losing
seal (Differential 1). When the fan starts, Differential 2 is equal
to the maximum negative static pressure.
Provide freeze-up protection as required.
Bottom Return Economizer Package (BREP)
and Horizontal Bottom Return Economizer
Package (HBREP) (39SR Unit) —
Economizers are
used with 39SR units for automatic sensor-controlled introduc-
tion of outdoor air into the system through an electro-mechani-
cally controlled damper.
To install BREP:
1. Check for correct number of parts shown in Fig. 17 and
the following list.
1 – Economizer assembly
1 – Barometric relief hood
1 – Outdoor air hood
1 – Hardware bag
2. Disconnect all power to unit.
3. Remove return air access panel from unit and rear access
panel(s) if applicable as shown in Fig. 18.
4. To assemble the barometric relief hood, the following
will be needed. See Fig. 19.
30 – Screws (type A no. 10 - 16 x
1
/
2
in.)
1 – 15 ft gasket (
1
/
8
in. x
1
/
2
in.)
1 – 15 ft gasket (
1
/
8
in.
x
3
/
4
in.)
a. Take hood bottom and left hood panel, putting the
flange of hood bottom to the inside of left hood
panel and screw into place.
Fig. 16 — Condensate Drain
FAN OFF
TRAP CONDITION WHEN FAN STARTS
FAN RUNNING AND CONDENSATE DRAINING
DIFFERENTIAL
1
DRAIN NIPPLE
DIFFERENTIAL
2
COOLING COIL
DRAIN PAN
H
Fig. 15 — Unit Suspension
VIBRATION ISOLATORS
(FIELD SUPPLIED)
CEILING – RECOMMENDED
PLATFORM MOUNT
a39-4081
CEILING – ALTERNATE
S
U
S
PEN
S
ION ROD
S
WITH NO MOUNT
a39-4088
a39-4125
