11
Testing Fuses and Buss Connections
1. Press
SET
and then press
/
to set emissivity to relatively high for paper covered fuse body or
insulated connections.
2. Press
YELLOW
button to select
MAX
.
3. Scan the paper covered length of fuse.
4. Without releasing the trigger, scan each fuse. Unequal temperatures between fuses may indicate voltage or
amperage imbalance.
5. Press
SET
and then press
/
to set emissivity to relatively low, for metal fuses and caps and insulated
buss connections.
6. Press
MODE
to select
MAX
.
7. Scan each end cap on each fuse.
Note: Unequal temperatures or a high temperature indicates loose or corroded connection through the fuse
buss spring clip
Testing Electrical Connections
1. Press
SET
and then press
/
to set emissivity to relatively low for
un-insulated connectors or buss connections or relatively high for insulated connections.
Note: Conductors are typically smaller than the thermometer’s spot size.
If the spot size is bigger than the connector, the temperature reading is the average within the spot.
2. Scan the conductor, moving toward direction of electrical connector (quick connector, wire nut, buss
connection, etc.).
Scanning Walls for Air Leaks or Insulation Deficiencies
1. Turn off heating, cooling, and blower.
2. Press
SET
to select emissivity. Press
/
to select emissivity relatively high for painted surfaces or
window surfaces.
3. Press
YELLOW
button to select
MIN
when opposite side of wall is at lower temperature and or select
MAX
when opposite side of wall is at higher temperature.
4. Measure an interior partition wall surface temperature.
5. Do not release the trigger. Record this temperature as your baseline (or benchmark) for a “perfectly”
insulated wall.
6. Face the wall to be scanned. Stand 1.5m away to scan a 4cm spot on the wall.
7. Scan horizontal rows of wall from top to bottom, or horizontal rows of ceiling from wall to wall. Look for
greatest deviations from baseline temperature to identify problems. This completes the insulation test scan.
Turn on the blower (no heat, no cooling) and retest. If test results with the blower on are different than results
with the blower off, this may indicate air leaks in conditioned envelope walls. The air leaks are caused by duct
leaks that create a pressure differential across the conditioned space envelope.
Testing Bearings
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Warning
To avoid injury when testing bearings:
1. Do not wear loose clothing, jewelry, or anything around neck when working around moving parts such as
motors, belts, blower, and fans.
2. Make sure an electrical disconnect is within reach and operating correctly and freely.
3. Do not work alone.
Note: It works best to compare two similar motors operating similar loads
