Maintenance
Mini-
Mite™ Tube Furnace
16
9.2
Overtemperature Alarm Protection (OTP)
The Load Overtemperature Alarm System indicates if the
temperature inside the chamber exceeds the load alarm
setpoint. To insure proper operation, this alarm system must be
checked at least once a month.
To test the load overtemperature alarm, complete the
following steps:
1. Operate the furnace without a product load at your normal
operating temperature.
2. Readjust main temperature control to a temperature above
the load alarm setting (refer to Section
s
6.2
, 7.2.1, 7.3.2 Step 13
).
3. Observe the unit closely until the load alarm trips, indicated
on the controller beside the Allabel.
4. Reset the main temperature control to normal operating
temperature. Once the unit cools below the alarm setpoint,
the Al indicator will go off.
9.3
Solid-State Relay Replacement
WARNING!
Disconnect furnace from main
power before attempting any maintenance to
furnace or its controls.
Refer to the Troubleshooting section for relay testing. If the
solid-state relay is inoperable, complete the following steps
to replace the relay (refer to Figure 5):
1.
Remove the screws located on the left and right sides of the
control panel (#1 in Figure 5).
2.
Slide the panel assembly away from the unit to expose
components.
3.
Locate the solid-state relay on the component tray (#2 in
Figure 5).
4.
Note the terminal connections of the relay wires and label them
for reattachment. Remove the wires from the relay terminals.
5.
Remove the mounting screws from the relay.
6.
Replace the relay and reconnect the wires.
7.
Reassemble the unit.
9.4
Power Relay Replacement
WARNING!
Disconnect furnace from main
power before attempting any maintenance to
furnace or its controls.
Refer to the Troubleshooting section for power relay
testing. If the power relay is inoperable, complete the
following steps to replace the relay (refer to Figure 5):
1.
Remove the screws located on the left and right sides of the
control panel (item #1 in Figure 5).
2.
Slide the panel assembly away from the unit to expose
components.
3.
Locate the power relay on the component tray (item #3 in
Figure 5).
4.
Note the terminal connections of the relay wires and label them
for reattachment. Remove the wires from the terminals of the
relay.
5.
Remove the mounting screws from the relay.
6.
Replace the relay and reconnect the wires.
7.
Reassemble the unit.
Figure 5. Solid State Relay Replacement
Summary of Contents for Mini-Mite TF550 A
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