Tweco ULTRAFEED VAF-4, Руководство по обслуживанию

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ULTRAFEED VAF-4
5-20 TROUBLESHOOTING Manual 0-5332
This protection circuit will also operate if there is a short circuit from the 110VAC or 42VAC supply down to earth.
Generally if this happens, the circuit breakers CB1 or CB2 would also trip removing all power from the wirefeeder.
The low level control signals from the 19 pin interconnection control cable connect to the Motor Control PCB1 via
header P4.
The Display PCB2 is connected to the Motor Control PCB1 via header P1 on both PCBs. A power supply signal and
a serial interface Can bus are used for connection.
The remote control signals from the front 8 pin control socket connect to the Motor Control PCB1 via header P6.
The Gun trigger connects to the Motor Control PCB1 via header P3.
The gas solenoid connects to the Motor Control PCB1 via header P5.
The motor tacho connects to the Motor Control PCB1 via header P2.
The motor positive is connected to P7 on the Motor Control PCB1. The motor negative is connected to P11 on the
Motor Control PCB1.
Art # A-12025
Figure 5-10 Control Circuit
The main DC bus is filtered by E4, E5 and E6.
From this, a flyback converter power supply provides all the regulated and isolated supplies for the PCB. Each out-
put from the power supply has an indicator LED to show if the supply is present, for easy faultfinding.
The power supply has an isolated 15VDC output, specifically for the trigger circuit. It has a 24VDC supply to power
the solenoid, and a 15VDC supply for the control electronics. It also has an is/-15VDC supply to power the
electronics on the “input” side of the flyback converter, so that all the main control electronics are fully isolated
from the incoming AC power, and any parts at welding voltage potential.
The output signals from the control electronics to drive the motor are opto-isolated, as the motor takes its power
from the main DC bus. The electronics to drive the motor incorporate measurement of motor current, and level
shifting to drive the mosfet pair. N12 is the motor drive mosfet, N16 is the motor braking mosfet.