Table 6 — Fan Contactor Coil Data
| UNIT | VOLTAGE | MAXIMUM |
| HOLDING |
| 40RU** | (vac) |
| VA |
| | |
| 25, 28, 30 | 24 | 10 |
Connecting Ductwork — Refer to the Carrier System Design Manual for the recommended design and layout of ductwork. Fig. 18 shows recommended duct connection to units with 2 fans.
UNIT OPERATION HAZARD
Failure to follow this caution could cause equipment damage.
Do not operate unit without ductwork or discharge plenum unless fan speed has been adjusted for external static pressure of zero in. wg. Failure to do so may result in motor overload.
DISCHARGE CONNECTIONS — Duct flanges are factory-supplied; they are shipped inside the unit attached to the hairpin end of the coil tube sheet for field installation. Using the existing screws, install the duct flanges on the unit’s fan deck. Each fan discharge requires 2 flanges; each flange must be bent in the middle to conform to the discharge opening. See Fig. 19. After flanges are installed, connect them to the supply duct using a canvas connection to prevent vibration. It is important that this connection be properly fabricated to prevent high air friction losses and air noise.
RETURN CONNECTION — When using return-air ductwork, route return-air duct to the unit’s return air inlet near the filter rack, using a canvas connection to prevent transmission of unit vibration. If the duct blocks off the unit’s access panel, provide a slip joint in the ductwork to permit
OUTDOOR-AIR INLET CONNECTION — Connect outdoor- air inlet to field-installed accessory economizer. Refer to Economizer Installation Instructions.
Return-Air Filters — Type and size of filters are shown in Tables 1A – 1D and are factory-supplied and factory- installed. In all units with 2 fans, a filter replacement tool (hook) is shipped inside the unit for field use when replacing filters. See the Service section for instructions on filter element replacement.
