White Rodgers 50T35-743 - Manual (Page 3)

3
WARNING
CAUTION
FIRE HAZARD
• Do not exceed the specified voltage.
• Protect the control from direct contact with water
(dripping, spraying, rain, etc.).
• Label all wires before disconnection when servic-
ing controls. Wiring errors can cause improper
and dangerous operation.
• Route and secure wiring away from flame.
Do not short out terminals on gas valve or pri-
mary control. Short or incorrect wiring may dam-
age the thermostat.
MOUNTING AND WIRING
All wiring should be installed according to local and na-
tional electrical codes and ordinances.
The control must be secured to an area that will experi-
ence a minimum of vibration and remain below the maxi-
mum ambient temperature rating of 175°F. The control is
approved for minimum ambient temperatures of -40°F.
Any orientation is acceptable.
Refer to the wiring diagram and wiring table when
connecting the 50T35 control to other components of
the system.
UL approved, 105°C rated 18 gauge, stranded, 2 /
64
”
thick insulation wire is recommended for all low voltage
safety circuit connections.
UL approved 105°C rated 16 gauge min., stranded, 4 /
64
”
thick insulation wire is recommended for all line voltage
connections.
Follow the appliance manufacturer’s recommended in-
stallation or service instructions.
SHOCK HAZARD
• Disconnect electric power before servicing .
• Ensure proper earth grounding of appliance.
• Ensure proper connection of line neutral and line
hot wires.
EXPLOSION HAZARD
• Shut off main gas to appliance until installation is
complete.
INSTALLATION
Remove both access panels.
For GMP & GMPV series units, cut the white jumper wire
between pins 4 & 7 of the 9 pin connector.
For GMPN & GMN series units, DO NOT cut the white
jumper wire.
Remove the edgecard connector and other wires from the
existing module. Discard the thermostat wires re-
moved from the board (R, W & G).
Remove the existing HSI module. Care should be exer-
cised to avoid damage to the nylon standoffs.
Install the 50T35-743 module.
Reconnect the edgecard connector making sure of good
contact.
Push the 9 pin connector into the HSI module. It can go in
only one way. DO NOT force.
Reconnect the supplied thermostat wires.
Remove the red wire from the 24 volt side of the secondary
side of the transformer and discard.
Remove the blue ground wire from the transformer. DO
NOT discard.
Remove the blue wire from the transformer and discard.
Connect the red wire from the 9 pin connector to "24 volt"
of the secondary side of the transformer.
Connect the blue wire from the 9 pin connector to "Com-
mon" terminal of the secondary side of the trans-
former. This wire has a piggy back terminal.
Connect the blue ground wire, which was previously
removed, also to the "Common" terminal of the trans-
former.
Replace the access panels.
Restore gas and electrical power to the furnace.
Verify the sequence of operation as noted in the furnace
manufacturers Installation & Operating Instructions.
Black
White
24 v. Red
Com. Blue
GND. Blue
TRANSFORMER
115v. Supply
The 50T35 has only one serviceable part–an automotive
type fuse, which protects the low voltage transformer from
damage if its output is short-circuited. If the fuse has
opened up, remove whatever caused the short circuit and
replace the fuse with the same type 3 Amp automotive
fuse. If the control does not operate correctly after replac-
ing the fuse, replace the entire 50T35 control. There are
no other user serviceable parts.