Repair

Overtemperature Switch

Read Warnings on page 4. Wait for heater to cool before repairing.

1. Turn main power OFF

. Disconnect power

supply.

2.Relieve pressure, page 13.

3.Wait for heaters to cool.

4.Remove heater shroud.

5.Disconnect one leadwire from overtemperature switch (359), FIG. 8. Test across switch with ohmme- ter. Resistance must be approximately 0 ohms.

6.If switch fails test, remove wires and screws. Dis- card failed switch. Apply thermal compound 110009, install new switch in same location on housing (351), and secure with screws (311). Reconnect wires.

NOTE: If wires need replacement, disconnect tempera- ture control module. See Table 2, page 26 and FIG. 6, page 26

Heated Hose

Refer to the heated hose manual for hose replacement parts.

Check Hose Connectors

1. Turn main power OFF

. Disconnect power

supply.

2. Relieve pressure, page 13.

NOTE: Whip hose must be connected.

3.Disconnect hose connector (D) at Reactor, FIG. 9.

4.Using an ohmmeter, check between the two termi- nals of the connector (D). There should be continu- ity.

5.If hose fails test, retest at each length of hose, including whip hose, until failure is isolated.

Check FTS Cables

1. Turn main power OFF

. Disconnect power

supply.

2.Relieve pressure, page 13.

3.Disconnect FTS cable (F) at Reactor, FIG. 9.

F

D

ti17788a

FIG. 9. Heated Hose

4.Test with ohmmeter between pins of cable connec- tor.

Pins

Result

 

 

 

 

1 to 2

approximately 35 ohms per 50 ft (15.2 m) of

 

hose, plus approximately 10 ohms for FTS

 

 

1 to 3

infinity

 

 

5. If cable fails test, retest at FTS, page 32.

3A1570A

31

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Graco A-25 Heated Hose, Overtemperature Switch, Check Hose Connectors, Check FTS Cables, Pins Result