Carrier 50FK, JK034-074 Start-Up, Modulating Power Exhaust Differential Pressure Switch Sizes

Fig. 33 Ð Modulating Power Exhaust and Inlet

Guide Vane Differential Pressure Switch

(Sizes 034-048)

Fig. 34 Ð Inlet Guide Vane Differential

Pressure Switch and Variable Frequency Drive

Duct Pressure Transducer (Sizes 054-104)

Fig. 35 Ð Modulating Power Exhaust Differential

Pressure Switch (Sizes 054-104)

MODULATING POWER EXHAUST Ð The tubing for the building pressure 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 pressures as possible.

A differential pressure switch (DPS) is used to control the actuator on the modulating discharge damper in exhaust fan no. 1. The building pressure (BP) DPS is located in the aux- iliary control box of the unit. See Fig. 33 and 35. Use a nomi- nal 3¤8-in. plastic tubing.

For instructions on adjusting BP control set points, refer to Start-Up, Modulating Power Exhaust section in this book.

START-UP

Initial Check

IMPORTANT: Do not attempt to start unit, even mo- mentarily, until all items on the Controls Start-Up Check- list (in installation instructions) and the following steps have been completed.

1.Verify unit has been installed per the Installation Instruc- tions included in the unit installation packet.

2.Verify that all auxiliary components (sensors, controls, etc.) have been installed and wired to the unit control boxes per these instructions, the unit Installation Instructions, and the unit wiring label diagrams.

3.Verify that air pressure hoses (static, duct, etc.) are prop- erly attached, routed, and free from pinches or crimps that may affect proper control operation.

4.Set any control con®gurations that are required (®eld- installed accessories, etc.). The unit is factory con®gured for all appropriate factory-installed options with the ap- plicable controls programmed to the default values.

5.Check and adjust unit set points. See Table 9.

6.Check tightness of all electrical connections.

7.Perform quick test (see Quick Test Program section on page 31).

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