Install Instructions
13
12.5 Low Voltage Connections
Several combinations of low volt age schemes are possible, depending on the presence of a heat kit and whether the heat kit is
single-st age or mult i-stage, whet her the out door section is an air conditioner or heat pump, and whether the out door section is
single-st age or two-st age. The 24V-control volt age connects the air handler to the room thermostat and condenser. Low volt -
age wiring must be copper conductors. A minimum of 18AWG must be used for inst allations up to 100 feet. Low voltage wiring
must be connected through the top of the cabinet or either side. See the “ Thermost at Wiring” section of this manual for typical
low volt age wiring connections.
12.5.1 Thermostats
Second-stage heat can be accomplished by a mult i-stage heating thermostat or the addit ion of an out door thermost at as show n
in wiring schemat ics on pages 14 and 15. Follow the thermostat manufacturer’s inst ructions for installation.
12.6 Speed Tap Adjustment
ARUF* * 14* * and ARPT* * 14* * air handlers have mult i-speed PSC mot ors. The color of the wire coming from the mot or to t he
“ COM ” terminal on the control board defines at which speed the mot or will operate. Black wire is high speed, blue wire is
medium speed and red wire is low speed. To change speeds, remove the wire attached to the “ COM ” terminal on the control
board, and swap it wit h the wire (on terminal “ M 1” or “ M 2” ) wit h the color that will give the desired speed.
ASPT* * 14* * and ASUF* * 14* * air handlers feature energy efficient blower mot ors. The mot ors run at a constant torque wit h
very low pow er consumpt ion and are energized by 24 VAC. Adjust the CFM by changing the 24 VAC leads to t he desired speed
tap on the terminal block. The ASPT blower mot or speeds are programmed to deliver adequat e airflow at rated ext ernal stat ic
pressure and with 60 second off time delay. For det ails, refer to the specification sheet applicable to your model.
NOTE: In some models, not all speed taps are allowable for cert ain electric heat applications. Refer to air handler Series and
Rat ings plate for minimum speed.
13 Achieving 2% Low Leakage Rate
Ensure all the gaskets remain intact on all surfaces as shipped with t he unit . These surfaces are areas bet ween t he upper t ie plate and
coil access panel, blow er access and coil access panels, and bet w een the coil access and filt er access panels. Ensure upon inst allat ion,
that the plast ic breaker cover is sitting flush on the blow er access panel and all access panels are flush with each ot her and the cabinet.
With these requirements sat isfied, the unit achieves less than 2% airflow leakage when tested in accordance with ASHRAE Standard
193.
14 Start-Up Procedure
• Prior to start-up, ensure t hat all electrical wires are properly sized and all connections are properly tightened.
• All panels must be in place and secured. For Air Tight applicat ion, gasket must be positioned at prescribed locations to achieve
2% leakage.
• Tubing must be leak free.
• Condensate line must be trapped and pit ched to allow for drainage.
• Low voltage wiring is properly connected.
• Auxiliary drain is inst alled when necessary and pit ched to allow for drainage.
• Unit is protect ed from vehicular or other physical damage.
• Ret urn air is not obtained from, nor are there any ret urn air duct joint s that are unsealed in, areas where there may be objec-
tionable odors, flammable vapors or product s of combust ion such as carbon monoxide (CO), which may cause serious personal
injury or deat h.
15 Regular M aintenance
The only it em required to be maint ained on a regular basis by the
user is t he circulat ing air filter(s). Filt er should be cleaned or re-
placed regularly, typically once per month. A certified service
technician must perform all ot her services.
IM PORTANT NOTE: If thumb screws are used to access t he filt er,
ensure the washer inst alled on the screw behind the access panel
remains in place after re-installat ion.
HIGH VOLTAGE!
Disconnect ALL power before servicing or
installing this unit. Multiple power sources may
be present. Failure to do so may cause property
damage, personal injury or death.