Current Sensor Board - PowerTec 2000C Instruction Manual

DNJ
DNJ
DNJ = DO NOT
ADJUST - THIS
IS A FACTORY
ADJUSTMENT
IOC ZERO
B ZERO
A ZERO
Figure 29: Parts layout and important points on the Current Sensor board 4001-144009-XXX.

6.3 CURRENT SENSOR BOARD

The Current Sensor Board (POWERTEC part
#4001-144009-XXX) contains circuits which moni-
tor the voltage across the capacitors:
1. When power is turned on, the Current Sensor
Board monitors the increase in voltage across the
capacitors and closes CR1 when voltage across the
charging resistor drops below about 35 VDC. CR1
stays in an energized state until the voltage across the
bus drops below 80% of nominal bus. An LED near P3
indicates when the relay is energized. An LED labeled
BUS CHARGED on the Current Controller board
(part # 4001-141108) changes from red to green when
the contactor is energized.
2. After power up, the Current Sensor Board
monitors the bus voltage. If the input power goes away
or if the bus falls to 85% of nominal (even for a short
time), the transistors are turned off and a timer begins
timing. If at the end of 80mS, the power has not
returned, the drive trips. If the timer trips, or if bus
voltage drops below 80%, or if bus voltage rises more
than 120% of nominal, an OV/UV indication is sent to
the Current Controller. An OV/UV will also be sent to
the Current Controller if an input power phase is lost.
The Current Sensor Board has three current
sensors mounted on it. They monitor flux around two
of the motor lead wires for current limit sensing, and
in the bus wire between the positive side of the
capacitor bank and the transistor collectors connected
to the positive side of the bus, which is bus current.
ALL ADJUSTMENTS ON THE CURRENT SENSOR
BOARD ARE FACTORY ADJUSTMENTS EXCEPT THE
OUTPUT ADJUSTMENT (P6)!
30
Page
TO + BUS
B
A
B SPAN
A SPAN
C
IOC ZERO B ZERO A ZERO
TO - BUS
TO PRECHARGE
RESISTOR
POWERTEC
UV TO OV HOT
THML
HEATSINK
HEATSINK
OVERVOLTAGE
UNDERVOLTAGE TIMED OUT
UNDERVOLTAGE
The bus current sensor is calibrated by the Trip
Calibrate resistor (located on TB3 terminals 1 and 2). This
resistor is installed by the factory using accurate instru-
ments and methods for a trip at 300% (instantaneous) of
the bus full load current. See section 2.1 (page 2-1) for
approximate value.
The HORSEPOWER CALIBRATION resistor (ter-
minals 4 and 5) may vary between units shipped from the
factory because load currents in motors of the same HP,
but at different base speeds, or enclosure types, etc, may
be different. Section 2.1 (page 2-1) gives nominal values.
The Current Sensor Board develops its own power
supplies (raw supplies come from the power transformer).
POSSIBLE PROBLEM:
CR1 DOES NOT ENERGIZE.
Check the BUS LED on the Current Controller Board. If on, check CR1
coil for +24VDC. If coil voltage is missing change the Current Sensor
Board. Otherwise, change CR1.
POSSIBLE PROBLEM:
IOC OR OV/UV LED ON THE CURRENT CONTROLLER BOARD
COMES ON WHEN BUS LED TURNS GREEN AT POWER UP.
1. Check to see if the HP CAL resistor has been installed on TB3. If not,
check Section 2-1 for proper value.
2. Check the voltage across C1 (+ side) and C2 (- side). Check against
the following table:
Nominal
AC input
voltage
230
380
460
3. Make sure all three phases are present at the input fuses.
P2
JP2
144-9
P3
RELAY
ON
OUTPUT ADJUST
TB3
Bus Voltage Bus Voltage
too low too high
less than more than
270 390
450 650
550 780
Model 2000C / 3000C Manual