Minster IOI, Руководство по обслуживанию

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To Calibrate The Digital
Percent Of Load Meter:
1. Before calibrating the meter, it will be necessary to
know the 100% or full load current rating of the drive
motor. This amperage figure is shown on the motor
specification tag. Take care when checking this item
to record only the full load current for the voltage
being applied. If the motor’s full load current (FLA)
is not known, check the specification tag before
starting the motor and record the amount.
2. Start the main drive motor. If output speed is
adjustable, set the speed control to a mid-range
position. Then allow time for the flywheel speed to
stabilize.
3. Using a clamp-on type ammeter, measure the cur-
rent flowing through one of the drive motor line
leads. Record this reading.
NOTE: The slide must not be cycled during this
amperage measurement.
4. To determine the percentage of full load current
being used by the motor, divide the ammeter read-
ing recorded in Step 3 by the full load current (FLA)
stamped on the motor specification tag.
Example:
FLA specification of the drive motor = 48 amps.
Ammeter measurement = 21.6 amps.
Percentage of load = 21.6 ÷ 48 = .45 or 45%
Therefore, the motor is using 45% of its full load
current.
5. While holding motor current at the same rate as
recorded in Step 3, adjust potentiometer and the
High/Low Range Switch (this switch effects circuit
adjustment gain only) so that the meter will display
the Percent Of Load amount calculated in Step 4.
SERVICING PROCEDURE:
In the event a problem is encountered with the Bul.
490-0248 Digital Percent Of Load Meter, perform the
following tests:
1. Check for the presence of 110 volts A.C. between
the “A.C.” meter terminals 1 (+) and 2 (-). (Voltage
must be present.)
2. Check for the presence of signal voltage between
the meter “INPUT” terminals 3 (+) and 4 (-). (Voltage
should range between 0 and 10 volts A.C. with the
drive motor running.)
Results Obtained:
If signal voltage is not present, or is present, but erratic:
1. Check for loose or broken wires attached to the cur-
rent transformers.
2. Check the current transformers for possible dam-
age, open or shorted windings.
3. If the power supply and signal voltages are present,
but the meter does not function, return it to Minster
for repair.
NOTE: Field repair of the Minster Bul. 490-0248
Digital Percent Of Load Meter is not recom-
mended; however, a parts list is available
from Minster upon request.
4. If the Digital Percent Of Load Meter is equipped with
an optional audible warning device, but the device
does not sound when the percentage of load
exceeds 100%, perform the following tests:
A. Check for the presence of 14 volts D.C.
(approx.) between terminals 5 (+) and 6 (-) on
the meter terminal strip at the same time the
meter is displaying a load in excess of 100%.
NOTE: Motor current will normally exceed
100% for full load while the motor is
accelerating from startup. If the press is
equipped with an Eddy Current Variable
Speed Drive, and the coupling control is
equipped with a torque limiter board, it
is normal for the motor current to pulse,
repeatedly, up to values nearing 150%
of full load while the output speed is
accelerating.
Results Obtained:
A. If proper voltage is read between “WARNING
Device” terminals 5 (+) and 6 (-) when the meter
is displaying a load of 100% or more, but the
audible warning device does not sound, replace
the audible warning device.
NOTE: Replace the audible WARNING device
with an identical type only.
B. If the meter indicates a current draw in excess of
100%, but no voltage is present between
“WARNING Device” terminals 5 (+) and 6 (-),
even with the audible device disconnected,
return the meter to Minster for repair.
When returning a unit to Minster for repair, make cer-
tain it is carefully packaged to protect it from damage
during shipment. Include, with the unit, a description of
the problems encountered and the serial number of the
press on which it is used. Also include your purchase
order covering the work to be performed and any spe-
cial shipping instructions concerning return of the unit.
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