Troubleshooting The Drive; Chiller Alert Codes; Chiller Alarm Codes; Test Equipment Needed To Troubleshoot - Carrier 19XRV Start-Up And Service Instructions

Troubleshooting the Drive

An isolated multimeter with diode tester is needed to measure DC
bus voltage and to make resistance and diode checks.
The drive can display two (2) kinds of error codes on the PIC6
HMI called Alert and Alarm codes. These codes signal a problem
detected during self-tuning or drive operation.
• A warning message on the HMI is an ALERT. The same
message when viewed with Danfoss' software MCT-10 is a
VFD WARNING.
• A failure resulting in a shutdown is seen as an ALARM on
the HMI and the VFD when viewed with Danfoss' soft-
ware MCT-10.
CONDITION CODES
CHILLER ALERT =VFD WARNING
CHILLER ALARM =VFD ALARM
See Tables 5 and 6.

CHILLER ALERT CODES

An alert condition is indicated by a message on the HMI screen.
The drive will continue to operate during the alert condition. In-
vestigate the cause of the alert to ensure it does not lead to a fault
condition. The alert code will automatically be cleared from the
HMI when the condition causing the alert no longer exists. See the
19XR Controls Operation and Troubleshooting manual for PIC6
controls.

CHILLER ALARM CODES

An alarm condition is also indicated by a message on the HMI
screen. If an alarm occurs, the drive coasts to stop. For the drive
to restart the underlying condition must be resolved and drive
must be Reset. This can typically be done from the PIC6 HMI by
resetting the Alarm. In rare instances the reset may need to be
done with Danfoss MCT-10 software or a customer-supplied
LCP (Local Control Panel). See the 19XRV Controls Operation
and Troubleshooting manual for PIC6 controls for chiller Alarm
codes.

TEST EQUIPMENT NEEDED TO TROUBLESHOOT

An isolated multimeter adequately rated for DC bus voltage will
be needed to measure DC bus voltage and make resistance checks.
Note that dedicated troubleshooting test points are not provided.

VISUAL INSPECTION FAULT TROUBLESHOOTING

When troubleshooting a unit which has been in service for an ex-
tended period of time do not assume that everything external to the
drive is fine. Look for issues such as loose connections, improper
programming. It is suggested to look at all the following:
• Cable routing; check for parallel routing of wires.
• Control wiring; check for broken or damaged wires and
connections. In parallel drive systems check connections
between the control shelf and the modules. Check the volt-
age source of the signals.
• Cooling; check operation of all cooling fans. Check the en-
closure filters. Check for blocked air passages. Check the
positive and negative interconnections between modules.
• DC fuse micro-switch; In parallel drive systems, check
that the micro-switches have been snapped properly on to
the DC fuse fixtures.
• DC fuse mounting; In parallel drive systems, check both
ends of DC fuses for loose connections.
• Interior; check that the drive is free of dirt, metal chips,
moisture, and corrosion. Check for burnt or damaged pow-
er components, or carbon deposits resulting from compo-
nent failure. Check for cracks in the housings of power
semiconductors, or for pieces of broken component hous-
ings inside the unit.
• Environmental; The drive can operate within a maximum
ambient temperature of 50°C (122°F) and a 24-hour tem-
perature limit of 45°C (113°F). Humidity levels must be
less than 95% non-condensing. Check for harmful airborne
contaminates such as sulfur-based compounds.
• Grounding; The drive requires a dedicated ground wire
from its enclosure to the building ground. Grounding the
motor to the drive enclosure is recommended. Check that
ground connections are tight and free of oxidation.
• Input power wiring; Check for loose connections, proper
fusing, and blown fuses.
• Motor; Check the nameplate ratings of the motor. Ensure
that the motor ratings correspond with the drive ratings.
Check that the motor parameters (parameter 1-20 Motor
Power [kW] to parameter 1-25 Motor Nominal Speed) are
set according to the motor ratings. It is sufficient to check
these values from the PIC6 configuration menu.
• Output to motor wiring; Check for loose connections.
Check for switching components in the output circuit.
Check for faulty contacts in the switchgear. In parallel
drive systems, check for proper interconnections between
the modules. Check cable length and cross-section imbal-
ance between the terminals of the modules. One missing
wire can cause an overcurrent trip.
• Programming; Make sure that drive parameter settings are
correct according to motor, application, I/O configuration.
• Proper clearance; Drives require adequate top and bottom
clearance to ensure proper airflow for cooling. Ensure that
no foreign elements are obstructing air flow.
• Vibration; Look for unusual amounts of vibration around
the drive.

VERIFY THAT DC BUS CAPACITORS ARE DISCHARGED

The drive's DC bus capacitors retain hazardous voltages after in-
put power has been disconnected. Perform the following steps be-
fore touching any internal components:
1. Turn off and lock out input power. Wait the appropriate
time as indicated on drive nameplate.
2. Verify that there is no voltage at the drive's input power
terminals.
3. Measure the DC bus potential with a voltmeter while
standing on a non-conductive surface and wearing insulated
gloves (1000 v). Measure the DC bus potential. The voltage
between DC+ and DC-, and from each DC terminal to the
chassis must be zero before proceeding. For parallel drive
modules, measure for DC-bus voltage before and after the
individual DC fuses.
4. Once the drive has been serviced, reapply input power.
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