Carrier 48ZT, ZN030-105, ZW, Z6, Z8075-105, 48ZG Auxiliary Control Box Location Sizes

Air Pressure Tubing — Before options such as inlet guide vanes (IGV), variable frequency drive (VFD), and/or modulating power exhaust can operate properly, the pneumatic tubing for pressure sensing must be installed. Use fire-retardant plenum tubing (field-supplied). All control devices use 1/4-in. tubing. Tubing must be run from the appropriate sensing loca- tion (in the duct or in the building space) to the control device location in the unit.

INLET GUIDE VANES — The tubing for the duct pressure (DP) control option should sample supply duct pressure about 2/3 of the way out from the unit in the main trunk duct, at a location where a constant duct pressure is desired.

The duct pressure is sensed by a pressure transducer. The output of the pressure transducer is directed to the unit control module. On all sizes, the DP transducer is located in the unit auxiliary control box. See Fig. 45 and 46 for auxiliary control box location. See Fig. 47 and 48 for auxiliary control box details. Use a nominal 1/4-in. plastic tubing.

VARIABLE FREQUENCY DRIVE — The tubing for the duct pressure (DP) control option should sample supply duct pressure about 2/3 of the way out from the unit in the main trunk duct, at a location where a constant duct pressure is desired.

On these units, the duct pressure is sensed by a pressure transducer. The pressure transducer output is directed to the unit control module. On all sizes, the DP transducer is located in the unit auxiliary control box. See Fig. 45 and 46 for auxiliary control box location. See Fig. 47 and 48 for auxiliary control box details. Use a nominal 1/4-in. plastic tubing.

Refer to appropriate base unit Controls and Troubleshooting book for instructions on adjusting set points for duct pressure controls.

MODULATING POWER EXHAUST — The tubing for the building pressure (BP) control (achieved via the modulating power exhaust option) should sample building pressure in the area near the entrance lobby (or other appropriate and sensitive location) so that location is controlled as closely to design pres- sures as possible.

These units use a pressure transducer for sensing building pressure. The BP transducer is located in the unit auxiliary con- trol box. See Fig. 45 and 46 for auxiliary control box location. See Fig. 47 and 48 for auxiliary control box details. Use a nom- inal 1/4-in. plastic tubing.

For instructions on adjusting BP control set points, refer to the Controls and Troubleshooting book.

RETURN/EXHAUST POWER EXHAUST — The tubing for the building pressure (BP) control (achieved via the return/ exhaust power exhaust option) should sample building pres- sure in the area near the entrance lobby (or other appropriate and sensitive location) so that location is controlled as closely to design pressures as possible.

The units use a pressure transducer for sensing building pressure. The BP transducer is located in the unit auxiliary con- trol box. See Fig. 46 for auxiliary control box location. Fig. 49 for auxiliary control box details. Use a nominal 1/4-in. plastic tubing.

For instructions on adjusting BP control set points, refer to the Controls and Troubleshooting book.

AUXILIARY

CONTROL

BOX

Fig. 45 — Auxiliary Control Box Location (Sizes 030-050)

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