Toshiba VT130G1 - Manual (Page 11)

Section 3
B. Regulator Board
Wiring diagrams at the end of this manual show a block diagram of regulator board
functions and adjustments.
The regulator board accepts operator information and outputs base signals to control
the Q-TR's. Refer to the wiring diagrams pages 14 and 15 for the following descriptions.
The operator speed pot. (frequency setting signal) is connected to CRF. REF. and OV.
0 to 12V DC at REF controls full range output of the inverter.
A 4 to 20mA signal can be connected at IRF and OV. A contact opening the CRF wire
of the speed pot. will automatically switch to this current reference. The cover mounted
speed pot. comes standard with this switch.
ST (start). F (forward), and R (reverse) connected to COM controls the start/stop func­
tion and direction of inverter output.
Fault relay (contacts at FLA, FLB, and FLC) latches on if a fault occurs. Pressing the reset
button or remotely resetting will reset the relay. (Remote reset use term. RST to COM)
A low speed relay may be used to detect inverter speed below as HZ. (option)
Factory adjustment provides 0.5 to 80 HZ operation. Moving jumper J3 from the 60
HZ to the 50 HZ position automatically changes maximum output to 67 HZ. Fre­
quency range is adjustable from 0.5 HZ to 80 HZ with 1F jumpered at J2. Jumping 2F
at J2 raises output frequency to 160 HZ and 4F at J2 raises output frequency to 320
HZ. Note that adjustments or changes in output frequency may require readjustment
of remote frequency meter and V/HZ.
The current detector monitors bus current from the HCT. If bus current rises to 163%,
stall prevention circuitry phases back both voltage and frequency until the current
decreases. 190% current shuts the Q-TR base drive off until current decreases. 240%
current turns base drive off and latches the fault relay and OC overcurrent display.
Bus voltage is monitored on the base drive board. Fast deceleration rates can cause
the bus voltage to rise when absorbing energy from the motor. If the bus voltage rises
to 750V (650V normal], deceleration time is lengthened regardless of setting. At Boov,
the inverter shuts down to protect filter capacitors C1 and Q-TRs from damage and
latches fault relay and OV display.
The microprocessor (CPU) develops base signals which are isolated and amplified by
the base driver circuit. Transformer T1 provides isolated low voltage A.C. which is rec­
tified and filtered for the base driver amplifiers.