PI Manufacturing AC generators - Manual (Page 17)

4.7.1.5 RAMP
AVR Type MX321
The RAMP potentiometer enables adjustment of the time
taken for the generator's initial build up to normal rated
voltage during each start and run up to speed. The
potentiometer is factory set to give a ramp time of three
seconds, which is considered to be suitable for most
applications. This time can be reduced to one second by
turning the pot. fully counter clockwise, and increased to eight
seconds by turning the pot. fully clockwise.
4.7.2 TRANSFORMER CONTROLLED
GENERATORS - TRANSFORMER ADJUSTMENT
Normally no adjustment is required but should the no-load
voltage and/or on-load voltage be unacceptable, adjustment
of the transformer air gap can be made as follows.
Stop the generator. Remove transformer cover box. (Normally
left hand side of the terminal box when viewed from the non
drive end).
Slacken the three transformer mounting bolts along the top of
the transformer.
Start the set with a voltmeter connected across the main
output terminals.
Adjust the air gap between the transformer top lamination
section and the transformer limbs to obtain required voltage
on no-load. Slightly tighten the three mounting bolts. Switch
load 'on' and 'off' two or three times. Application of load will
normally raise the voltage setting slightly. With the load 'off'
recheck the no-load voltage.
Readjust air gap and finally tighten mounting bolts.
Refit the access cover.
Failure to refit covers can result in
operator personal injury or death.
4.8 ACCESSORIES
Refer to the "ACCESSORIES" - Section 6 of this Manual for
setting up procedures related to generator mounted
accessories.
If there are accessories for control panel mounting supplied
with the generator refer to the specific accessory fitting
procedures inserted inside the back cover of this book.
Warning !