Specifications

27
TROUBLESHOOTING
Troubleshooting the Motormaster® V control requires a
combination of observing system operation and VFD display
information. Refer to Table 10 for status indicators and
Table 11 for fault codes.
If the liquid line pressure is above the set point and the VFD
is running at full speed (60 or 50 Hz), this is a normal condi-
tion. The fan can not go any faster to maintain set point.
The MMV also provides real time monitoring of key inputs
and outputs. The collective group is displayed through parame-
ters 50-56 and all values are read only. These values can be
accessed without entering a password.
1. Press MODE twice and P50 will appear.
2. Press MODE again to display value.
Use UP and DOWN keys to scroll through parameters
P51-P56 then press MODE to display the value.
• P50: FAULT HISTORY — Last 8 faults
• P51: SOFTWARE version
• P52: DC BUS VOLTAGE — in percent of nominal. Usu-
ally rated input voltage x 1.4
• P53: MOTOR VOLAGE — in percent of rated output
voltage
• P54: LOAD — in percent of drives rated output current
rating
• P55: VDC INPUT — in percent of maximum input:
100% will indicate full scale which is 5 v
• P56: 4-20 mA INPUT — in percent of maximum input.
20% = 4 mA, 100% = 20 mA
If a fault lockout (LC) has occurred, view the fault history in
P50 to find the last fault. Once P50 is displayed, use the arrow
keys to scroll through the last 8 faults. Any current faults or fault
codes from the fault history can be analyzed using Table 11.
The drive is programmed to automatically restart after a
fault and will attempt to restart three times after a fault (the
drive will not restart after CF, cF, GF, F1, F2-F9, or Fo faults).
If all three restart attempts are unsuccessful, the drive will trip
into FAULT LOCKOUT (LC), which requires a manual reset.
To disable automatic control mode and enter manual speed
control mode:
1. Change P05 to ‘01- keypad’.
2. Push UP and DOWN arrow key to set manual speed.
3. Set P05 to proper value to restore automatic control
according to Table 9.
To provide manual start/stop control:
With power removed from VFD, remove start command
contact and install a switch between the appropriate start termi-
nals as required in Table 8.
EPM Chip — The drive uses a electronic programming
module (EPM) chip to store the program parameters. This is an
EEPROM memory chip and is accessible from the front of the
VFD. It should not be removed with power applied to the
VFD.
Liquid Line Pressure Set Point Adjustment —
Adjusting the set point is not recommended due to possible
interaction with other head pressure software algorithms or
controls. In situations where the set point must be changed, the
set points for R-22 and R-134a operation are found in P34 and
P35. A higher value will result in a higher liquid line set point.
Example: increasing the R-22 set point from 24.0 to 25.0 will
increase the liquid line pressure by approximately 10 psi.
Loss of CCN Communications — Carrier Comfort
Network (CCN) communications with external control
systems can be affected by high frequency electrical noise gen-
erated by the Motormaster V control. Ensure unit is well
grounded to eliminate ground currents along communication
lines.
If communications are lost only while Motormaster V con-
trol is in operation, order a signal isolator (CEAS420876-2)
and power supplies (CEAS221045-01, 2 required) for the CCN
communication line.
Table 10 — Status Indication
FAULT FAULT NAME DESCRIPTION
CL
CURRENT LIMIT The output has exceeded the CURRENT LIMIT setting (Parameter 25) and the drive is
reducing the output frequency to reduce the output current. If the drive remains in
CURRENT LIMIT for too long, it can trip into a CURRENT OVERLOAD fault (PF).
Er ERROR Invalid data has been entered.
GE
GE “GE” will be displayed if an attempt is made to change the OEM default settings when the
drive is operating in the OEM mode (see Parameter 48).
LC FAULT LOCKOUT Failed three restart attempts. Requires a manual reset.
SP START PENDING This is displayed during the first 15 second interval between restart attempts.