Monessen Hearth DLY18, Installation And Operating Instructions Manual

Page: 19 / 34

19
Checking System Operation
The millivolt system and individual
components may be checked with a
millivolt meter having a 0-1000MV
range. Conduct each check shown in
chart below by connection meter test
leads to terminals as indicated.
CHEC K
TEST
A
B
TO
TEST
COMPLETE
SYSTEM
THERMOPILE
OUTPUT
CONNECT
METER
LEADS TO
TERMINALS
2 & 3
1 & 2
THERMOSTAT
CONTACTS
CLOSED
OPEN
METER
READING
SHOULD BE
CLOSED
OPEN
A. Complete Millivolt System Check ("A" Reading - Thermostat contacts CLOSED - Control Knob
"ON" - Main burner should be come ON)
a. If the reading is more than 100 millivolts and the automatic valve still does not come on - replace the control.
b. If the closed circuit reading ("A" reading) is less than 100 millivolts, determine cause for low reading - proceed
as follows:
B. Thermopile Output Reading Check ("B" Reading - Thermostat contacts OPEN - Main burner OFF)
1. CP-2 system - 325 millivolts minimum. If the minimum millivolt reading is not obtainable, readjust pilot for
maximum millivolt output. If millivolt reading is still below minimum specified, replace thermopile.
Figure 15: Wiring Diagram
The DL series Milli-Volt (thermopile) is a self powered combination gas control, does not require
110vac to operate. Refer to Figure 15 and installation instructions provided with optional wall switch,
thermostat or remote control for wiring instructions. A maximum length of 20 feet of 18awg two
conductor wire is to be used for wall switch or thermostat installations. Note thermostats and switches
must be suitable for millivolt operation.
Switch
On/Off
Switch
On/Off
Switch
ODS
Pilot
Wall
Switch
CAUTION
Label all wires prior to
disconnection when ser-
vicing controls. Wiring er-
rors can cause improper
and dangerous opera-
tion. Verify proper opera-
tion after servicing.
Optional Wall
Switch, Thermostat
or Remote
ELECTRICAL WIRING (Millivolt)
ODS Pilot
Millivolt
Valve
Red
Red