AVPTC Installation Manual

10
NOTE: The Temperature Rise Tables can also be used to estimate
the air handler airflow delivery. When using these tables for this
purpose set the room thermostat to maximum heat and allow
the system to reach steady state conditions. Insert two
thermometers, one in the return air and one in the supply air.
The temperature rise is the supply air temperature minus the
return air temperature. Using the temperature rise calculated,
CFM can be estimated from the TR formula above. See Spec
Sheets and/or Service Manual for more information.
13 Electrical and Control Wiring
IMPORTANT: All routing of electrical wiring must be made
through provided electrical knockouts. Do not cut, puncture or
alter the cabinet for electrical wiring.
13.1 Building Electrical Service Inspection
This unit is designed for single-phase electrical supply only.
DO NOT OPERATE ON A THREE-PHASE POWER SUPPLY. Mea-
sure the power supply to the unit. The supply voltage must
be measured and be in agreement with the unit nameplate
power requirements and within the range shown.
Nominal Input Minimum Voltage Maximum Voltage
208-240 197 253
ELECTRICAL VOLTAGE
Table 6
13.2 Wire Sizing
Wire size is important to the operation of your equipment.
Use the following check list when selecting the appropriate
wire size for your unit.
FIRE HAZARD!
To avoid the risk of property damage, personal injury
or fire, use only copper conductors.
HIGH VOLTAGE!
Failure to do so may cause property damage,
personal injury or death.
Disconnect ALL power before servicing.
Multiple power sources may be present.
HIGH VOLTAGE!
To avoid property damage, personal injury or death
due to electrical shock, this unit MUST have an
electrical ground. The
electrical ground circuit may consist of an
appropriately sized electrical wire connecting the
ground lug in the unit control box to the building
electrical service panel.
Other methods of grounding are permitted if performed
in accordance with the National Electric Code
(NEC)/American National Standards Institute
(ANSI)/National Fire Protection Association (NFPA) 70
and local/state codes. In Canada, electrical grounding
is to be in accordance with the Canadian Electric Code
(CSA) C22.1.
uninterrupted, unbroken
• Wire used must carry the Minimum Circuit Ampacity
(MCA) listed on the unit’s Series and Rating Plate.
• Refer to the NEC (USA) or CSA (Canada) for wire sizing.
The unit MCA for the air handler and the optional electric
heat kit can be found on the unit Series and Rating Plate.
• Wire must be sized to allow no more than a 2% voltage
drop from the building breaker/fuse panel to the unit.
• Wires with different insulation temperature rating have
varying ampacities - be sure to check the temperature rat-
ing used.
Refer to the latest edition of the National Electric Code or
in Canada the Canadian Electric Code when determining
the correct wire size.
13.3 Maximum Overcurrent Protection (MOP)
Every installation must include an NEC (USA) or CEC
(Canada) approved overcurrent protection device. Also,
check with local or state codes for any special regional re-
quirements.
Protection can be in the form of fusing or HACR style circuit
breakers. The Series and Rating Plate provides the maxi-
mum overcurrent device permissible.
NOTE: Fuses or circuit breakers are to be sized larger than
the equipment MCA but not to exceed the MOP.
13.4 Electrical Connections – Supply Voltage
IMPORTANT NOTE: USE COPPER CONDUCTORS ONLY.
Knockouts are provided on the air handler top panel and
sides of the cabinet to allow for the entry of the supply
voltage conductors, as shown in Figure 13. If the knockouts
on the cabinet sides are used for electrical conduit, an
adapter ring must be used in order to meet UL1995 safety
requirements. An NEC or CEC approved strain relief is to
be used at this entry point. Some codes/municipalities re-
quire the supply wire to be enclosed in conduit. Consult
your local codes.
Side of
Cabinet
Top of
Cabinet
KNOCK-OUT FOR ELECTRICAL CONNECTIONS
Figure 13