User Guide

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Operation
Press for 1 second to power ON/OFF.
Tap to zero measurements.
LED Color Indications
Green slow blink: normal operation
Red slow blink: batteries need to be replaced
Supply or Return Side Switch
The Job Link® System app knows which side
you have selected for each probe. Select P1 or
P2 and place it on the system appropriately.
Static Pressure
Static pressure testing ensures if the
equipment is operating within factory
specications.
1 Zero your JL3MN while in ambient pressure
with any tubing/probes attached before tak-
ing measurements. For measurements less
than 2 inWC, take reading within 1 minute
after zeroing for best accuracy.
2 Use the included static pressure tip when
checking static pressure in an airow stream.
NOTE: The red arrow on the static probes should
point toward the airow of the stream.
3 Place a JL3MN before and after the lter to
measure your lter pressure drop (
B
A
).
4 Place a JL3MN before and after the coil to
measure your coil pressure drop (
D
C
).
5 Place a JL3MN in the inlet and outlet air of
the equipment to measure your total external
static pressure (
C
B
). Check with manufac-
turer to determine TESP test locations.
NOTE: If you are in an environment where the
temperature is noticeably changing while
you are taking your reading, it is advised that
you disconnect the probe from the tubing
and ZERO it relative to the ambient air before
each reading.
Gas Pressure
Prevent symptoms like rough starts or
overheating your heat exchanger by checking
your gas pressure.
1 See manufacturer's specication for target inlet
and outlet fuel or gas pressures.
2 Shut o main gas supply power to furnace.
4 Zero your JL3MN while at ambient pressure
with tubing attached before taking measure-
ments.
5 Remove outlet pressure tap screw and insert
the brass screw tting of the hose into the
outlet pressure tap of the gas regulator.
NOTE: Some pressure
taps have a 5/16''
boss instead of an
insert screw. In this
case, use the
included 5/16''
adapter tube. Loosen
the tap screw about
1 revolution and slide
the tube over the boss.
6 If you suspect high or low inlet pressure to the
regulator, connect the JL3MN to the inlet tap.
7 Put furnace into operation and begin to take
measurements.
Auto Power O (APO)
The probe will automatically power o after
2 hours. To disable APO until powered o, while
power is on tap twice. The LED will briey
blink red. To enable APO, while power is on tap
twice. The LED will briey shine red.
Adapter
(5/16'' to 3/16'')
FILTER
BLOWER
COIL
C
O
IL
Point Ti
p
Toward
Airflow
FILTER
P2
(Return)
(Red)
P1
(Supply)
(Blue)
B
A
C
D