Repair; Primary Thermostat & Probe; Backup Thermostat - Graco VISCON HP 309524L Instructions Manual

Repair

Repair
WARNING
Read warnings, pages 4-5. Make sure the main power
is off and heater is cool before repairing.
Hazardous Location Heaters: See F
Non-hazardous Location Heaters: See F
Primary Thermostat & Probe
1. Follow Pressure Relief Procedure, page 14.
2. Remove housing cover (18).
3. Hazardous Location Heater only: Loosen nut (27).
Non-hazardous Location Heater only: Loosen
screws (25).
4. Loosen setscrew (26) in switch shaft (28).
5. Remove screw (16) and bracket (19) holding probe
(EE).
6. Remove wires from the primary thermostat termi-
nals (FF).
7. Pull thermostat probe (EE) out of heater block (3).
Remove thermostat (24) from housing (1).
8. Hazardous Location Heater only: Remove screws
(25).
Non-hazardous Location Heater only: Remove
screw standoff (35) with washer (27).
9. Remove bracket from thermostat (24) and secure to
new thermostat.
18
To avoid damaging capillary tube (GG), which can
cause heater malfunction, do not kink or nick the tube.
To avoid shorting out the heater, do not allow capillary
tube to contact the block terminal (3A). Follow step
10, below.
. 15 & 17
IG
10. Liberally apply thermal lubricant (part no. 110009) to
. 16 & 18
IG
11. Continue reassembling in reverse order of disas-

Backup Thermostat

1. Follow Pressure Relief Procedure, page 14.
2. Remove housing cover (18).
3. Remove screws (HH) on backup thermostat (10)
4. Remove the two screws (16), then remove the ther-
5. Liberally apply thermal lubricant (part no. 110009) to
CAUTION
probe (EE) of new thermostat (24). Loop capillary
tube (GG) several times and wrap the loops with tie
strap (42-not shown). Insert probe in the heater
block (3).
sembly. See Reassembly Notes, below.
tabs, and remove the wires – one from heater block
(3A) and one from line in (9B).
mostat (10).
the bottom of the thermostat (10) and reinstall it in
reverse order of disassembly.
Reassembly Notes
• Refer to F . 15 or 16 for wiring connections.
IG
• Non-hazardous Location Heater only: Make
sure gasket (47) is installed and aligned with
electrical housing screw holes.
• Secure cover (18) with lockwashers (5) and
screws (6 or 52); torque screws to 89 in-lb (10
N•m).
309524L