Carrier Aero 39MN Series Installation, Start-Up And Service Instructions Manual page 237

ALARMS (GREEN LED FLASHING) — For less severe
errors, called alarms, the diagnostic display is advisory. For
these situations, the drive is simply reporting that it had detect-
ed something unusual. In these situations, the drive:
• flashes the green LED on the drive (does not apply to
alarms that arise from control panel operation errors)
• sets an appropriate bit in an Alarm Word parameters
(0308 or 0309)
• overrides the control panel display with the display of an
alarm code and/or name
Alarm messages disappear from the control panel display
after a few seconds. The message returns periodically as long
as the alarm condition exists.
CORRECTING FAULTS — The recommended corrective
action for faults is shown in the fault codes listing in Table 52.
The VFD can also be reset to remove the fault. If an external
source for a start command is selected and is active, the VFD
may start immediately after fault reset.
To reset a fault indicated by a flashing red LED, turn off the
power for 5 minutes. To reset a fault indicated by a red LED
(not flashing), press RESET from the control panel or turn off
SYMPTOM
Steam trap is not functioning properly.
The header P-traps are not draining.
The steam line has been taken from
the bottom of the steam source or is
not sloped properly.
The steam main is overloaded with water.
Water is spitting from the
discharge manifolds
Vertical discharge manifolds are not plumb. Make manifolds plumb.
Horizontal headers are not level.
Vertical discharge manifolds are
installed upside down.
Check valve sizing to maximum
manifold capacity.
Valve is not open.
There is no steam available.
Steam does not There is a change in steam pressure.
discharge from the
manifolds when the valve
is open
Steam is not visible.
Y-strainer may be clogged.
AHU — Air-Handling Unit
Table 50 — Humidifier Troubleshooting
POSSIBLE CAUSES
237
the power for 5 minutes. Depending on the value of parameter
1604 (FAULT RESET SELECT), digital input or serial com-
munication could also be used to reset the drive. When the fault
has been corrected, the motor can be started.
HISTORY — For reference, the last three fault codes are
stored into parameters 0401, 0412, 0413. For the most recent
fault (identified by parameter 0401), the drive stores additional
data (in parameters 0402 through 0411) to aid in troubleshoot-
ing a problem. For example, a parameter 0404 stores the motor
speed at the time of the fault. To clear the fault history (all of
Group 04, Fault History parameters), follow these steps:
1. In the control panel, Parameters mode, select parame-
ter 0401.
2. Press EDIT.
3. Press the UP and DOWN button simultaneously.
4. Press SAVE.
CORRECTING ALARMS — To correct alarms, first deter-
mine if the Alarm requires any corrective action. Action is not
always required. Use Table 53 to find and address the root
cause of the problem.
POSSIBLE REMEDIES
Clean or replace non-functioning steam trap on the valve/trap
assembly.
Clean and check that plumbing runs to gravity drain. Check that trap
height exceeds the static pressure of the duct/AHU, especially if it is
under negative pressure.
Change line to take off from the top and check proper slopes.
Locate cause and correct problem.
Make headers level.
Reinstall correctly.
Resize valve within manifold capacity.
Open valve.
Verify that steam is available.
Verify that the steam pressure has not changed. Excessively high
pressure could jam the valve.
Carefully place a mirror or metal object close to one of the steam dis-
charge slots. If it fogs, steam is discharging, but evaporating very
quickly. This is not a problem. NEVER PLACE YOUR HAND OVER
OR NEAR THE STEAM DISCHARGE SLOTS.
Clean or replace Y-strainer.