Operating Options; Millivolt Control System - Lennox Hearth Products Ravelle 30 Installation And Operation Manual

Operating Options
Your Ravelle™ 30 gas fireplace comes equipped with an "On/Off" rocker
switch used to turn the burner on and off while the pilot light is on. The
switch is a round rocker switch located behind the lower door of the
fireplace's face.
A wall-mounted switch, a millivolt wall thermostat can be used to supple-
ment the rocker switch. The gas valve is powered by millivolts generated
by the pilot assembly. This millivolt system is very sensitive to electrical
resistance, therefore make sure all connections are tight, clean and free
from corrosion. Do not splice any millivolt wires. Consult the table on
this page to determine the proper gage of wire for the thermostat or wall
switch connections. This table refers to the total length of the wire (out to
the switch and back). The thermostat must be a millivolt type. A 24-volt
furnace thermostat will not work. Never hook up household current - 120
Volts - to the millivolt system. It is not recommended to hook up any
more than two switches to the fireplace (for example a rocker switch and
a wall thermostat). Additional switches may affect the system resistance
and increase the chance of the burner not igniting.
Follow the instructions included with the thermostat for wiring. The ther-
mostat and rocker switch will turn the burner on and off independently. Be
sure to set the rocker switch to the "Off" position when using the thermostat
and set the thermostat to the lowest temperature when you wish to use
the rocker switch only, otherwise one may override the other.
Millivolt Control Schematic
Piezo Igniter
Gas Inlet
Figure 36
Pilot Hood
Sparker
Thermocouple
Pilot Gas Line
White
Brown
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Wire Size
1 Gage
14 Gage
16 Gage
18 Gage
0 Gage
Millivolt Control System
This fireplace operates on a millivolt control system. As such, no addi-
tional power supply is needed for the fireplace to heat. The pilot assembly
contains a thermocouple, that when heated by the pilot flame, generates
electricity (millivolts- mV=1/1000 of a volt) which opens a valve allow-
ing gas to flow to the pilot assembly. The pilot assembly also contains a
thermopile, that when heated by the pilot flame, generates electricity that
flows to terminal #1 (labeled THTP) on the gas valve. When the electricity
is conducted from terminal #1 through the on/off switch, thermostat to
terminal #3 (labeled TH) on the gas valve, the main burner will ignite.
Thermopile
Pilot Assembly
ON/OFF Rocker Switch
or Thermostat
Thermostat Wire
Maximum Length
100 Feet
64 Feet
40 Feet
5 Feet
16 Feet
Wiring Terminals
TH
TP
TH/TP
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