GE VALUTROL MAIN CONTROL MODULE Instructions Manual page 24

GEK-24994
Monitor FC and adjust
CROSS
CW until FC Just starts to
Increase
CROS$
may be checked when the drive is running
in normal operation by venfymg that CEMF reads the value
on the test data sheet with the dnve operating above base
speed.
LIN TIME
(linear time)
Momtor TR and set to zerO wIth the
LOCREFpotentlOmeter.
Rapidly turn the
lOC REF
full Fwd and measure the tIme for
TR to ramp to 10 volts(±10%). Adjust
LIN TIME
until this
tImt> corresponds to the test data sheet lmear time.
COMP
(compensation - IR)
Set the
LOC REF
potentIOmeter to center position. Adjust
the
CUR
REF
potentIOmeter Fwd or Rev until CFB IS at 5
volts (±1O%).
Momtor CEMF and adjust
COMP
untIl CEMF equals the
value on the test data sheet.
CUR LIMIT
(current limit)
Set
CUR LIMIT
full CWo Adjust the
CUR REF
potentIOmeter
untIl CFB corresponds to the current limit level on the test
data sheet. Momtor DR and turn
CUR liMIT
CCW until DR
Just moves away from zero.
IMET
(load instrument calibration)
Adjust the
CUR REF
until CFB corresponds to full load
current. Venfy that the optional load instrument reads full
load. If not, remove power; adjust
IMET
and repeat.
Set the
lOC REf
to the center posItion; reset the drive
and sWItch to DiagnostIc Run.
CEMF LIMIT
(counter emf limit)
Turn
CEMF liMIT
full CCW and turn the
LOC REF
potentIOmeter full Fwd. Adjust
CEMF LIMIT
until CEMF
corresponds to the
CEMF liMIT
on the test data sheet.
MAX SPEED/AlION
(max speed/tachometer loss allgn-
fault).
Turn
MAX SPEED
full CWo Turn
ALIGN
full CWo Adjust
the
lOC REF
potentiometer until CEMF reads 5 volts (±1O%)
Adjust
MAX SPEED
until SFB corresponds to the base speed
feedback on the lest data sheet.
Momtor T A and adjust
ALIGN
CCW until T A is
approxImately zero volts.
24
SMET
(speed instrument calibration)
Turn the
LOCREFpotentiometer
until SFB is3 volts (±1O%).
The optional speed mdicator should mdicate 30% top
speed. If It does not, push the RESET button to initiate a
shut down. Remove power, adjust
SMET
and repeat.
Return the DIagnostic Switch to Normal.
REF SCALE/MAX SPEED
(reference scale/max speed)
Turn
REF SCALE
full CCW. Start the drive and apply top
speed reference to SR. Adiust the REFSCALEpotentiometer
until SFB is
l{)
volts (±1O%). This normalizes the tImed
reference TR and speed feedback, SFB for 10 volts(±l0% )at
top speed
Now measure motor RPM and adjust
MAX SPEED
(if
necessary) until the actual RPM corresponds to the desired
top speed. If actual top RPM was off by more than 5% reset
ALIGN
as detailed above.
RSTOP
(regenel"ative stop)
WIth the mom tor operatmg at some RPM, call for a drive
stop by initiating the proper magnetics which
will
release
2TB-14 from -30 volts. The motor will decelerate to a low
speed and the contactor will open. If the contactor opens
before the drive comes down to a stop,
RSTOP
is set too far
CWo If the contactor fails to open,
RSTOP
is set too far
CCW. Push the RESET button to drop out the contact or
prior to removmg power.
RSTOP
should be readjusted with
power removed.
MIN SPEED
(minimum speed)
Reduce the system reference to minimum and start the
drive. Adjust
MIN SPEED,
as required, to meet system
minimum speed reqUIrements. Refer to system elementary
for CIrcuit details.
GAIN. RESPONSE. DAMP
and
COMP
(Stability
adjustments)
1 Set
DAMP
potentiometer at minimum 7 o'clock
position.
2. Place the Diagnostic switch in the static mode. Adjust
CUR REF
for 2.5 volts at test pin CFB. This is
eqUivalent to rated armature current.
3. Set
COMP
potentiometer by reading at the CEMF test
pin a value equal to 0.0312 (240V - motor CEMF)
for 240V drives. For SOOV drives use .0148 (SOOV -
motor CEMF).
TypIcal values of motor counter EMF: