24
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT
®
SERIES DIRECT-VENT GAS FIREPLACES • MODELS MLDVT-30/35/40/45 • INSTALLATION INSTRUCTIONS
Step 4. FIELD WIRING
B. Electronic Wiring (see
Figure 38
)
Note: The electronic appliance must be con-
nected to the main power supply.
1. Route a 3-wire 120Vac 60Hz 1ph power
supply to the appliance junction box.
2
. Remove the electrical inlet cover plate from
the side of the unit by removing the plate's
securing screws (see Figure 13 on
Page
10).
3
. Remove the cover plate’s knockout and then
feed the power supply wire through the
knockout opening and into the unit junction
box.
4
. Connect the black power supply wire to the
lower outlet's
red pigtail lead and the white
power supply wire to the
common
terminal
of the outlet as shown in Figure 38.
5
.
Connect the ground supply wire to the pig-
tail lead attached to outlet’s green ground
screw.
6.
Appliance-mounted ON/OFF burner control
switch (rocker switch) is factory installed
behind the bottom panel.
Optional wall-mounted switch, thermostat, or
one of the optional remote control kits may
also be used. The appliance mounted ON/OFF
switch needs to be relocated onto the optional
style view door, if used.
TP-TH
TP
TH
APPLIANCE- MOUNTED
ON/OFF SWITCH
(OPTIONAL)
BK/W(1)
BK/W(1)
WALL-MOUNTED ON/OFF SWITCH (OPTIONAL)
THERMOSTAT (OPTIONAL)
JUNCTION BOX
BLACK
W
GR
120
V
AC
WALL MOUNTED CONFIGURATION FOR FAN SWITCH (OPTIONAL)
BK
R
WIRING DIAGRAM MILLIVOLT GAS VALVES
THERMOPILE
GAS VALVE
FAN
(OPTIONAL)
Figure 37
Figure 38
JUNCTION BOX
W
GR
BK
120 VAC
BK
R
TRANSFORMER 3V
INTERMITTENT ELECTRONIC WIRING DIAGRAM
BROWN
BROWN
BLACK
BATTERY BACK-UP
BLACK (SENSOR)
BLACK (IGNITER)
SPARK TO PILOT IGNITER
IGNITER MODULE
3V
RED
BK W GR
OPTIONAL BLOWER
SWITCH
FAN
(OPTIONAL)
PILOT
IN
OUT
VENT
LO
HI
TH
TP
TH
TP
IN
ORANGE (THTP)
BLACK (TP)
GREEN (TH)
TO WALL
SWITCH OR
THERMOSTAT
Refer to Section A for millivolt appliances and
Section B for electronic appliances. The gas
valve is set in place and pre-wired at the factory
on both models.
A. Millivolt Wiring (see
Figure 37
)
1.
Appliance-mounted ON/OFF burner control
switch (rocker switch) is factory installed
behind the bottom panel. Optional wall-
mounted switch, thermostat, or one of the
optional remote control kits may also be
used.
2
. If wall-mounted ON/OFF control switch ther-
mostat is selected, mount it in a convenient
location on a wall near the fireplace.
3. Wire the control switch within the millivolt
control circuit using the 15 feet of 2 conductor
wire supplied with the unit.
Note: The supplied 15 feet of 2 conductor
wire has one end of each conductor con-
nected to the gas valve circuit and the other
end of each conductor placed loose inside
the bottom compartment.
4
. If an optional control switch is installed,
turn the appliance-mounted ON/OFF burner
control switch to the OFF position.
CAUTION: Do not connect the optional wall
switch to a 120V power supply.
CAUTION
Ground supply lead must be con-
nected to the wire attached to the
green ground screw located on the
outlet box. See
Figure 38
. Failure to
do so will result in a potential safety
hazard. The appliance must be
electrically grounded in accordance
with local codes or, in the absence of
local codes, the National Electrical
Code, ANSI/NFPA 70-latest edition.
(In Canada, the current CSA C22-1
Canadian Electrical Code).
CAUTION: Label all wires prior to disconnec-
tion when servicing controls. Wiring errors
can cause improper and dangerous operation.
ATTENTION: Au moment de l'entretien des
commandes, étiquetez tous les fils avant
de les débrancher. Des erreurs de cáblage
peuvent entraîner un fonctionnement
inadéquat et dangereux.
Verify proper operation after servicing.
S’assurer que l'appareil fonctionne
adéquatement une fois l'entretien
terminé.
See Figure 39 for detailed drawing of junction box / receptacle wiring
