Rheem Manufacturing 1x2000, Installation Instructions Manual

Page: 18 / 36

TURN OFF ELECTRIC POWER AT
THE FUSE BOX OR SERVICE PANEL
BEFORE MAKING ANY
ELECTRICAL CONNECTIONS.
ALSO, THE GROUND CONNECTION
MUST BE COMPLETED BEFORE
MAKING LINE VOLTAGE
CONNECTIONS. FAILURE TO DO
SO CAN RESULT IN ELECTRICAL
SHOCK, SEVERE PERSONAL
INJURY OR DEATH.
IMPORTANT: THE FURNACE MUST
BE INSTALLED SO THAT THE
ELECTRICAL COMPONENTS ARE
PROTECTED FROM WATER
(FURNACE CONDENSATE).
ELECTRICAL CONNECTIONS
THE CABINET MUST BE
PERMANENTLY GROUNDED. A
GROUND SCREW IS PROVIDED IN
THE JUNCTION BOX FOR THIS
PURPOSE. FAILURE TO DO SO CAN
RESULT IN FIRE, ELECTRICAL
SHOCK, PERSONAL INJURY OR
DEATH.
The electrical supply requirements are
listed on the furnace rating plate.
Use a separate fused branch electrical
circuit containing a properly sized fuse
or circuit breaker. Run this circuit
directly from the main switch box to an
electrical disconnect which must be
readily accessible and located within
sight of the furnace. Connect from the
disconnect to the junction box on the
left side of the furnace, inside the
control compartment. See appropriate
wiring diagram.
NOTE: The electrical junction box
inside the furnace control compartment
may be relocated to the right side if
necessary. A knockout is provided.
IMPORTANT: L1 (hot) and L2 (neutral)
polarity must be observed when
making field connections to the
furnace. The ignition control on electric
ignition models will not sense flame if
L1 and L2 are reversed.
Installation of the electric supply line
should be in accordance with the
National Electric Code ANSI/NFPA No.
70, latest edition, or Canadian
Electrical Code Part 1 - CSA Standard
C22.1 and local building codes.
This can be obtained from:
National Fire Protection Association
Batterymarch Park
Quincy, MA 02269
Canadian Standards Association
178 Roxdale Boulevard
Roxdale, Ontario, Canada M92 1R3
WARNING
!
WARNING
!
ELECTRICAL WIRING
ELECTRONIC NIGHT SETBACK
THERMOSTATS ARE COMPATIBLE
WITH THE FURNACE CONTROL
SYSTEM. SOME MAY REQUIRE AN
ISOLATION RELAY.
If an isolation relay is needed, install it
as close to the control board as
possible. Use a single-pole, single-
throw relay with a 24-volt operating
coil. The relay contacts should be
designed for 24-volt loads.
Connect one end of the operating coil
to the thermostat “W” terminal.
Connect the other end of the coil to the
“C” terminal on the control board. See
Figure 14.
Connect one side of the normally open
contacts to the control board “W”
terminal.
When the thermostat calls for heat, it
powers the 24-volt operating coil. This
closes the relay contacts and conducts
power from terminal 3 and 4 to terminal
“W” on the control board and starts the
furnace ignition sequence.
A single or two stage thermostat may
be used, however a two-stage
thermostat is recommended for
optimum performance.
The room thermostat must be
compatible with the integrated furnace
control on the furnace. All thermostats
available from the furnace
manufacturer’s Parts Department are
acceptable. Generally, all thermostats
that are not of the “current robbing”
type are compatible with the integrated
furnace control we use.
HEAT ANTICIPATOR SETTINGS
If a current reading taken at the
thermostat is not performed, an initial
setting of .15 amps is recommended.
Adjust as needed to improve comfort
level.
ISOLATION RELAY
IMPORTANT: USE OF AN
ISOLATION RELAY WITH THE TWO
STAGE FURNACE SHOULD NOT BE
REQUIRED, BUT NOT ALL
THERMOSTAT
FIELD WIRE SIZE FOR 24 VOLT THERMOSTAT CIRCUITS
SOLID COPPER WIRE - AWG.
3.0
2.5
2.0 16
16
18 14
14
16 12
12
14 10
12
12 10
12
12 10
10
10
50 100 150 200 250 300
Length of Run – Feet (1)
Thermostat Load - Amps
①
The total wire length is the distance from the furnace to the
thermostat and back to the furnace.
NOTE: Do not use 24 volt control wiring smaller than No. 18.
18
FIGURE 14
ISOLATION RELAY
ST-A0804-01