The following information is provided to assist in the installation of power and control wiring. These requirements are in addition to and do not supersede any local code or project documentation requirements. It is the installer's responsibility to ensure that all work meets the project specification and local code requirements.
All units are shipped with a unit-mounted wiring diagram and nameplate. Consult these for electrical information prior to beginning any work on the unit.
Only professionally trained, qualified, and licensed (where required) personnel should work in the electrical box or on any control or power wiring. High voltage power wiring presents a signficant risk of injury or death.
Incorrect wiring may result in signficant damage to the unit and is not covered by warranty. Ensure that all wiring is landed at the proper points of connection as indicated on the wiring diagram. Do not power additional devices from the control transformers and do not power additional loads from the power wiring unless specifically noted.
Power to the unit must be disconnected when making downstream power connections, rephasing the unit at the power block, and making sensor and control connections. Failure to disconnect power may result in damage to the equipment and injury or death.
AboveAir Technologies units are shipped from the factory with components selected and internally wired for the specified electrical requirements. Refer to the unit’s nameplate for the voltage, phase, and frequency information. Prior to beginning wiring, verify that the main electrical service to be routed to the unit and the nameplate information are properly coordinated.
Check the unit nameplate for the full load amps (FLA), minimum circuit ampacity (MCA), and maximum overcurrent protection (MOP). Select wire and fuse sizes in accordance with Local and National code requirements. Improper wire sizing may result in fire or other failures; improper breaker sizing may result in a lack of protection (oversized breaker) or nuisance trips (undersized breaker).
The main power connection to packaged units or split unit sections must be made through a disconnect. The disconnect may be either factory provided or field provided and either non-fused or fused; refer to the submittal for more information.
Do not route wiring in a manner that will block service access to the unit. Electrical panels may be hinged to allow service access to the unit. Carefully plan the routing of all wiring to ensure that any hinged panels are allowed to rotate freely and completely on their hinges and provide proper strain relief to accommodate this rotation.
Verify power wiring connection requirements with as-built wiring diagram. Units will typically require 2 conductors (single phase units) or 3 conductors (3 phase units) plus ground. 3 phase units with single phase, sub-1HP motors may require a neutral connection.
Every unit is equipped with a ground lug. The unit must have an unbroken connection to ground in accordance with NEC and local electrical code. Do not use the ground lug for connecting a neutral conductor.
The unit is phase checked at the factory during testing; compressors, fans, and all other components are phased together. If a fan or compressor is running backwards when unit is connected to power, change phase at main power block. Do not re-phase individual components.
Units may be provided with single point power options for electric heaters or other accessories. These items may only be connected downstream of the branch circuit protection (either fuse block or breaker) provided by AboveAir Technologies. Do not power additional items from the unit where protection has not been provided.
AboveAir Technologies units are shipped from the factory with all internal components pre-wired. Terminals are provided for all field-wired connections. Refer to wiring details on the wiring diagrams, auxiliary device connections section, and controller information for more information.
Control wiring is 24 VAC and typically powered via 50VA or 75VA control transformers. Select wire sizes in accordance with Local and National code requirements. Do not use control power to power any additional field-supplied devices unless specifically noted on the wiring diagram. Dry contacts are provided for field power and wiring to field-wired components.
Do not route wiring in a manner that will block service access to the unit. Electrical panels may be hinged to allow service access to the unit. Carefully plan the routing of all wiring to ensure that any hinged panels are allowed to rotate freely and completely on their hinges and provide proper strain relief to accommodate this rotation.
Sensor wiring should use shielded, stranded cable with 3-5 conductors as required for the sensor. Wiring should be sized as follows:
Optional points of connection include a smoke detector, water detector, condensate pump, firestat, and remote stop-start. For all of these points, they must be NC (normally powered) via the unit’s 24VAC control circuit for unit operation. These terminals are factory labeled and jumpered; if a point is not used, the jumper must remain in place.
Analog control signals (0-10 VDC) are polarity sensitive. Failure to observe polarity may result in improper operation and damage to sensors or other devices.
Sensors should be installed as follows:
MC Series controls include a display terminal for unit interaction and control. The display may be mounted in the space, mechanical room, or at the unit (there are no sensors in the display). The display terminal is connected to the controller via a factory-provided telephone style cable. 50 feet of cable is included as standard; lengths up to 200 feet may be ordered from the factory. Route this cable with the same care as all other wiring. Damage to the display cable may result in failure of controller or display terminal and is not covered under warranty.