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2. Press .
3. Press .
4. Press .
5. Set TARGET VFD SPEED to 0%.
Verify that the ACTUAL VFD SPEED shown on the VFD dis-
play is within 0 to 1 Hz.
1. Press the softkey on the VFD keypad until all
LEDs on the left side of the keypad are illuminated.
NOTE: The value displayed is the frequency at which the
VFD is being commanded to operate.
2. Adjust VFD parameter P.009 (Input Offset) if outside the
tolerance.
To confirm that the speed signal from the CVC/ICVC
corresponds to the value displayed at the VFD:
3. Verify that the actual speed signal feedback to the chiller
controller is 0% by accessing the COMPRESS screen.
4. Verify ACTUAL SPEED VFD is 0%-1% on CVC/ICVC.
5. Adjust VFD parameter r.002 (Analog Output Offset) if
outside the tolerance.
Set VFD TARGET VFD SPEED to 100%.
1. Press .
2. Press .
3. Press .
4. Press .
5. Set TARGET VFD SPEED to 100%.
Verify that the ACTUAL VFD SPEED shown on the VFD dis-
play corresponds to the 50 Hz or 60 Hz setting.
1. Check the ACTUAL VFD SPEED configuration (50 Hz
or 60 Hz) on the ISM_CONF screen.
2. Confirm that the VFD displays the configured line fre-
quency within ± 1 Hz.
3. Adjust parameter P.010 (Input Gain) if outside the
tolerance.
4. Release the TARGET VFD SPEED so that it can operate
in automatic mode. (Refer to Override Operations section
on page 16.)
VFD CONTROL VERIFICATION (Running)
Preparation
1. Disconnect power to the VFD. Verify that the branch dis-
connects or other local disconnects are open and properly
tagged out.
2. Connect a voltmeter and ampmeter to the line side of the
VFD. Locate meters safely away from the power cables.
3. Reconnect power to the VFD.
4. Measure the voltage on the line side of the drive.
5. Verify it is within 10% of the chiller nameplate voltage.
6. Set up the CVC/ICVC temperature controller per the re-
quirements of the job.
7. Start the chiller and verify the rotation of the compressor
just as it starts.
8. Allow the chiller to load up. Verify that the chiller loads
up smoothly.
NOTE: One or two surges may be counted during the first
minute of operation.
Verify That Actual VFD Speed is 100% (±2%)
1. Set the VFD speed to 100%.
2. Verify that the ACTUAL VFD SPEED is 100% (± 2%).
3. If outside the tolerance, adjust r.003 (Output Analog
Gain).
4. Leave running for the next test.
ISM Current Calibration Check
1. With the target VFD speed at 100%, load the chiller so
that the CVC/ICVC default display shows 75% to 100%
under the display title AMPS %. A higher load is
preferred.
2. Measure the incoming current with a separate amp meter.
3. Calculate the line side error ratio using the following
equation:
4. If the Line Side Error Ratio is greater than ± 0.02 adjust
the CVC/ICVC reading by adjusting the ISM CT
ratio.
5. Shut down the chiller.
Change CT Ratio
1. New CT Ratio = Present CT Ratio multiplied by (1+ Line
Side Error Ratio).
To access the ISM_CONF screen:
2. Press .
3. Press .
4. Enter the password 1111.
5. Select ISM (STARTER) CONFIG DATA.
6. Enter password 4444.
7. Select ISM_CONF.
8. Change present CT ratio to new ratio using calculation
above.
9. Press to the softkey to save changes.
10. Press the softkey to exit the ISM_CONF screen.
11. Repeat ISM Current Calibration Check.
VFD Current Control Calibration Check
1. With the target VFD speed at 100%, load the chiller so
that the CVC/ICVC default display shows 75% to 100%
under the display title AMPS %. A higher load is
preferred.
2. Access the current on the keypad of the VFD. Determine
the Load Side Current Ratio, using the equation below.
Load Side Current Ratio =
Next, access the VFD Load Factor on the Capacity Con-
trol screen. Calculate the Load Side Error Ratio using the
equation below:
3. If the load side error ratio is greater than ± 0.02, adjust the
VFD load factor by changing the VFD current limit on
the Setup 2 screen.
a. The new VFD current limit = old VFD current
limit multiplied by (1+ Load Side Error Ratio).
b. Recheck the VFD Current Control Calibration.
c. Release the Speed Control by accessing the TAR-
GET VFD SPEED control.
Press .
Press .
Press .
(Refer to Override Operations section on page 16.)
STATUS
COMPRESS
SELECT
ENTER
MENU
STATUS
COMPRESS
SELECT
Amp Meter current – Ave. ISM current
Amp Meter current
VFD Actual Load Amps
Motor Nameplate Amps
Load Side
Error Ratio
=
VFD Load Factor – Load Side Current Ratio
Load Side Current Ratio
ENTER
SERVICE
SAVE
EXIT
MENU
STATUS
COMPRESS