Test Products International 275 - Manual (Page 33)

33 32
Application Notes (AC Amps)
When measuring AC Amps of a motor there
are two types of measurements that can be
made, running current and in-rush or start-up
current. Start-up current will usually be much
higher than running current.
Set up the meter following the steps under
“Measurement Procedure” on page 17, and
then proceed with the following:
• Clamp the meter around a single wire
and reconnect power to the device. Read
the current displayed on the meter. This
is the running current of the motor.
• Disconnect power to the motor and put
the meter in PEAK HOLD mode.
Reconnect the power and read
the current displayed on the
meter. This is the in-rush or
start-up current
of the motor.
When measuring resistance of a motor, make
sure the power is disconnected prior to testing.
Set up meter following steps under
“Measurement Procedure” on page 16, and
proceed with the following:
• Connect the red test lead to one power
input line of the motor and the black test
lead to the other power input line of the
motor. In most applications if the reading
is OFL, the motor winding is open.
• Connect the red test lead to the frame of
the motor and the black test lead to the
winding. In most applications if a reading
of 0 Ohms is displayed, the winding is
shorted to the motor frame (ground).
Application Notes (Resistance)