12
Install Electrical Connections
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
The unit cabinet must have an uninterrupted, unbroken
electrical ground. This ground may consist of an electrical
wire connected to the unit ground screw in the control
compartment, or conduit approved for electrical ground
when installed in accordance with NEC, NFPA 70
American National Standards Institute/National Fire
Protection Association (latest edition) (in Canada, Canadian
Electrical Code CSA C22.1) and local electrical codes.
!
WARNING
HIGH--VOLTAGE CONNECTIONS
The unit must have a separate electrical service with a
field--supplied, waterproof disconnect switch mounted at, or within
sight from, the unit. Refer to the unit rating plate, NEC and local
codes for maximum fuse/circuit breaker size and minimum circuit
amps (ampacity) for wire sizing.
The field--supplied disconnect may be mounted on the unit over
the high--voltage inlet hole (See Fig. 5 and 6).
NOTE
:
Field supplied disconnect switch box should be
positioned so that it does not cover up any of the unit gas
combustion supply air louvers.
Operation of unit on improper line voltage constitutes abuse and
may cause unit damage that could affect warranty.
UNIT COMPONENT DAMAGE HAZARD
Failure to follow this caution may result in damage to the
unit being installed.
1. Make all electrical connections in accordance with NEC
NFPA 70 (latest edition) and local electrical codes
governing such wiring. In Canada, all electrical
connections must be in accordance with CSA standard
C22.1 Canadian Electrical Code Part 1 and applicable
local codes. Refer to unit wiring diagram.
2. Use only copper conductor for connections between
field--supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.
3. Be sure that high--voltage power to unit is within
operating voltage range indicated on unit rating plate.
4. Insulate low--voltage wires for highest voltage contained
within conduit when low--voltage control wires are in
same conduit as high--voltage wires.
5. Do not damage internal components when drilling
through any panel to mount electrical hardware, conduit,
etc.
!
CAUTION
ROUTING POWER LEADS INTO UNIT
Use only copper wire between disconnect and unit. The high
voltage leads should be in a conduit until they enter the duct panel;
conduit termination at the duct panel must be watertight. Run the
high--voltage leads through the power entry knockout on the
power entry side panel. See Fig. 5 and 6 for location and size. For
single--phase units, connect leads to the black and yellow wires.
CONNECTING GROUND LEAD TO GROUND SCREW
Connect the ground lead to the chassis using the ground screw on
the control plate near the inducer switch (See Fig. 11).
GROUND SCREW
(IN SPLICE BOX)
YEL
BLK
GROUND
LEAD
SINGLE-PHASE
CONNECTIONS
TO DISCONNECT
PER NEC
LEGEND
NEC – National Electrical Code
Field Wiring
Splice Connections
NOTE: Use copper wire only.
L1
L2
A06299
Fig. 11 -- Line Power Connections
ROUTING CONTROL POWER WIRES
For detailed instruction on the low voltage connections to the User
Interface (UI), refer to the UI installation guide.
Form a drip--loop with the control leads before routing them into
the unit. Route the low voltage control leads through grommeted,
low--voltage hole provided into unit (See Fig. 5 and 6). Connect
user interface leads to unit control power leads as shown in Fig. 14.
The unit transformer supplies 24--v power for complete system
including accessory electrical heater. A fuse is provided in the
24--v circuit as a protection device (See Fig. 17 and 18).
Transformer is factory wired for 230--v operation. If supply voltage
is 208--v, rewire transformer primary as described in Special
Procedures for 208--v Operation section.
The furnace board is fused by a board--mounted automotive fuse
placed in series with transformer SEC1 and R circuit. The C circuit
of transformer circuit is referenced to chassis ground through a
printed circuit run at SEC2 and gas valve grounding wire. Check to
be sure control board is mounted securely using both
factory--installed screws.
OUTDOOR AIR TEMPERATURE SENSOR (OAT)
EQUIPMENT OPERATION HAZARD
The installation of an outdoor air temperature sensor (OAT)
using the Evolution control board OAT terminals is
required. Many Evolution features (auto humidity control,
comfort rollback, etc.) will be lost if the OAT is not
connected.
For detailed mounting instructions for the OAT sensor,
please refer to installation instructions shipped with the
OAT.
!
CAUTION
The OAT input is used to supply outdoor temperature data for
system level functions and for temperature display on User
Interface (UI). Using two wires of the field--supplied thermostat
wire cable, wire the ends of the two black OAT pigtails. Wire the
opposite ends of these two wires to the OAT provided with the UI.
There is no polarity to be observed.
NOTE
: Mis--wiring OAT inputs will not cause damage to either
Evolution control or thermistor. If the thermistor is wired
incorrectly, no reading will appear at UI. Re--wire thermistor
correctly for normal operation.
Two options for mounting the OAT sensor
1. Adjacent Building Structure
2. Under the Unit
677D
--
--
A
