Carrier 48AJ installation instructions Route VAV Static Pressure Sensors

ECONOMIZER

HOOD

LOCATION BAROMETRIC RELIEF OR POWER EXHAUST “SIDE #2”

23.28”

TYP

“END #2”

“SIDE #1”

“END #1”

23.28”

42.62”

42.62

TYP

ALTERNATE LOCATION (END)

R/A S/A

a48-8244

42.56”

ECONOMIZER

HOOD

42” MIN.

12.94

R/A(UNIT

OPENING)

S/A

J BOX

PLENUM RATED CABLE

(FIELD SUPPLIED)

J BOX

NOTE: 020-050 SIZES SHOWN (2 POWER EXHAUST FANS). SIZES 051 AND 060 HAVE 3 POWER EXHAUST FANS. ALL UNIT SIZES HAVE THE SAME SIZE POWER EXHAUST.

Fig. 31 — Power Exhaust Relocated to Side Return Duct

a48-3808

NOTES:

1.Unless otherwise specified, all dimensions are to outside of part.

2.Dimensions are in inches.

3.On 48AW,AY units, accessory barometric relief or power exhaust must be mounted in the field-supplied return ductwork.

Fig. 32 — Barometric Relief Damper and Power Exhaust Mounting Details

Step 11 — Route VAV Static Pressure Sensors

VAV DUCT PRESSURE TRANSDUCER — The VAV duct pressure transducer (VAV inverter pressure transducer) is locat- ed behind the filter access door on the lower inner panel. See Fig. 33. A section of field-supplied 1/4-in. plastic tubing must be run from the high pressure tap on the differential pressure switch and connected to a field-supplied tap in the supply-air duct. The tap is usually located 2/3 of the way out on the main supply duct. Remove plug button in panel to route tubing.

VAV BUILDING PRESSURE TRANSDUCER — The VAV building pressure transducer (modulating power exhaust pres- sure transducer) is located behind the filter access door on the

lower inner panel. See Fig. 33. A section of field-supplied 1/4-in. plastic tubing must be run from the high pressure tap on the differential pressure switch to the conditioned space. The pressure tube must be terminated in the conditioned space where a constant pressure is required. This location is usually in an entrance lobby so that the building exterior doors will open and close properly. Remove plug button in panel to route tubing.

The low pressure tap is factory-routed to the atmosphere. For a positive-pressure building, route the high tap to building air and low tap to atmosphere. For a negative-pressure

34