Instruction Manual

Larson Electronics, LLC
Phone: [phone]
Fax: [phone]
www.larsonelectronics.com
6 of 10
STATIC PHASE CONVERTER INSTRUCTION SHEET
OPERATION
For multiple motor applications, the largest motor must
always start first, and it must be at least 50% larger than any
other motor starting on the same converter, or if they start
simultaneously the combined horsepower of all the motors
must fall within the rating of the converter.
Always start a machine out of gear or in lowest spindle speed at
initial hook-up to reduce load. The static converter has a built-in
weak link, which is designed to fail rapidly if hooked to a higher
horsepower motor. On lower horsepower motors the light could
stay on after the motor is running, causing rapid failure of the
converter, thus providing protection against possible motor da
mage.
The red indicator light should turn on once the motor starts
and remain on until the OFF button is pressed. When testing the
static converter for the first few times after installation, keep
your hand near the off switch of the machine, ready to turn
it off to prevent damage to the converter due to a wrong or
loose connection.
Power may be left on the converter without the load
applied. Current draw is approximately 8mA (.008 amp). The
converter operates best when mounted vertically. Installation
should be performed by a qualified electrician. Refer to
local codes for proper wire sizing. Wires and fuses
should be sized as appropriate for the motor’s rated
amperage.
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TROUBLESHOOTING
A. If the motor fails to start and any of the following
symptoms occur: clicking noises from the static converter,
light flashes on and off and motor just hums or buzzes, motor
starts intermittently; this could indicate that either the motor is
wired for 460V or the static converter being used is too high
in horsepower for the motor, and a smaller size converter
should be tried.
B. No voltage when measured across lines B and C without
motor running: Normal indication.
C. Converter occasionally hums when motor is off: Normal.
Static Phase Converter used to start an Idler Motor, Idler Motor
to power the load motor.
Full or close to full horsepower (HP) can usually be obtained by
powering the load motor through a 3-phase motor that runs on
single-phase. A static phase converter is used to start the idler
motor. The idler motor windings act as a rotary transformer or
generator and consume little power when running unloaded. Used
motors are inexpensive and readily available. A single machine or
complete shop can be operated with great flexibility using this
method. The idler motor should be at least 50% larger than the
largest motor you want to run to accommodate the higher starting
current. A good quality 3450 RPM, Y-wound, 3 phase, 220V motor
is the best choice. A 1725 RPM motor can be used on applications
not heavily loaded.
1. Wire the static phase converter to the idler motor as described
in Method No. 1, side 1.
2. Size fuses and wires on the single-phase side as appropriate
for the motor’s rated amperage. Once running, the idler motor
can then power the load motor. Wire the load motor in parallel
to the idler motor as per Method No. 2 diagram below. Size
fuses and wires on the 3-phase side as appropriate for the
motor’s rated amperage.
3. Resistive or single-phase loads and/or magnetic switch gear
must be energized only by lines A and C from the converter.
Extra Precautions for Idler Motor System
Heavy starting load motor(s) may cause the output voltage of the
idler motor on line B to drop sufficiently to cause the static converter
to return to the start-up mode. At this point, the converter’s start
circuit has the combined horsepower of the idler motor and load
motor(s). This will be indicated by the light on the converter coming
on when the load motor is started. If the combined HP is greater
than the converter’s max. HP range, DAMAGE TO THE
CONVERTER MAY OCCUR.
To prevent damage to the converter, install a heavy-duty, single-
pole switch on line B between the static phase converter and the 3-
pole switch - refer to Method No. 2 diagram below. Switch should be
rated the same amperage as the idler motor, or greater. The switch
must be in the “ON” (closed) position before the idler motor is
started, and turned to the “OFF” (open) position after the light on the
converter has gone out. This will prevent the converter from
switching to the start-up mode and from being damaged by an
overload. Never turn the single-pole switch to the “ON” position while
the Idler Motor is running. Doing so could do damage to the
converter.
Larson Electronics, LLC.
9419 US-HWY 175
Kemp, Tx. 75143
800-369-6671 • FAX [phone]
www.larsonelectronics.com
E-mail: [e-mail]
220V
SINGLE
PHASE