DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE INSTRUCTIONS
Section I. REPAIR PARTS, SPECIAL TOOLS, AND EQUIPMENT
5-1. Tools and Equipment.
The equipment issued with the heater assembly is il-
5-3. Maintenance Repair Parts.
Repair parts and equipment are listed and illustrated
in the repair parts and special tools list covering direct
5-2. Special Tools and Equipment.
support and general support maintenance for this
No special tools or equipment is required for direct sup-
equipment. Refer to TM 5-4520-240-24P.
port or general support maintenance of the heater as-
Section Il. TROUBLESHOOTING
to direct support and general support maintenance
a. This section contains troubleshooting information
for locating and correcting most of the operating trou-
bles which may develop in the space heater. Each mal -
The ignition system of this space
function is followed by a list of tests or inspections
heater contains dangerous voltages
which will help you determine probable causes and cor-
rective actions to take. Perform the tests/inspections
which can cause severe e l e c t r i c a l
and corrective actions in the order listed.
shock. Be extremely careful when
b. This manual cannot list all malfunctions that may
making voltage measurements or
occur, nor all tests or inspections and corrective ac-
other checks with the heater connected
tions. If a malfunction is not listed or is not corrected
to the power source during
by listed corrective actions, notify your supervisor.
Only those functions which are solely within the scope
troubleshooting. Always remove the
of direct support and general support maintenance are
power plug before making any con-
5-5. Direct Support and General Support
Maintenance Troubleshooting Chart.
Before you use this table, be sure you have performed
all applicable operating checks.
Refer to table 5-1 for troubleshooting which is allocated
Table 5-1. Direct Support and General Support Troubleshooting
TEST OR INSPECTION
1. HEATER FAILS TO START (NO FLAME, NO BLOWER).
Step 1. Remove top and side cover panels, and pull out control panel. With power connected, turn the heater on and check that the time
delay assembly heats.
Replace the time delay assembly (para 6-2 thru 6-4) if it fails to become noticeably warm within 45 to 70 sec-
Step 2. With power on, briefly jumper yellow and green leads on terminal block.
If blower begins to run, replace the time delay assembly (para 6-2 thru 6-4).
Step 3. Disconnect power plug and allow time delay assembly to cool. Press RESET button and check continuity between two red leads
Replace the time delay assembly if the switch is open after reset (para 6-2 thru 6-4).
Step 4. Check control relay continuity using an ohmmeter (para 7-3.
Replace a defective control relay (para 7-2 thru 7-4).
Step 5. Check ignition power supply for high voltage output.
Repair or replace ignition power supply (para 8-2 thru 8-4).
2. HEATER IGNITES BUT BLOWER FAILS TO RUN.
Step 1. Turn power on, wait for time delay, and check for 28 vdc across motor terminals using a multimeter set to read de voltage.
Replace control relay if there is no power for motor terminals. Refer to paragraph 7-2 thru 7-4.
Step 2. Disconnect motor leads at plug in connector and motor ground terminal. Connect to external source of 28 vdc.
Replace motor if it fails to run.