![](http://pdfasset.owneriq.net/d/c1/dc15c158-f040-4c8f-a35b-7d9ade3ec824/dc15c158-f040-4c8f-a35b-7d9ade3ec824-bg4d.png)
6
Troubleshooting
Troubleshooting l 6-11
Passive Alarms
Problem
P5 Return Air High
Temperature – If the return air
temperature is between 150
and 180°F (65.6 and 82.2°C).
P6 Regen High Temperature
– If the regeneration tempera-
ture exceeds the high tempera-
ture limit for the specified
time. Default values are
450°F (232.2°C) for 20 sec.
P7 Regen Low Temperature
– The regeneration tempera-
ture is less than the low tem-
perature setpoint for the speci-
fied time. Defaults are 350°F
(176.7°C) for 20 sec.
P8 Regen Temperature Loop
Break – The regeneration tem-
perature is outside of the oper-
ator entered deviation alarm
band (see Regen Temperature
Deviation passive alarm) and
the regeneration temperature
is not moving towards the set-
point at a rate greater than
specified. Default values are
36°F (2°C) over 20 sec.
Possible cause
The hopper does not contain enough
material.
You are drying at a high drying tempera-
ture (above 250°F [121.1°C]) or running
at low throughputs.
If an optional aftercooler is installed, it
does not have enough water.
The aftercooler coils are dirty.
The air hose connections are loose.
One of the solid state relays (SSRs)
failed in the closed position.
The regeneration RTD is loose or has
fallen out.
The regeneration heater has failed.
The regeneration RTD is loose or has
fallen out.
The return air RTD has failed.
The regeneration heater has failed.
The regeneration RTD is loose or has
fallen out.
Solution
Make sure your material supply system
is working properly.
Add an optional aftercooler, if one is not
currently installed.
Turn on the water supply, or fix any
leaks or blockages.
Clean the aftercooler coils.
Tighten all air hose connections.
Replace the failed solid state relays
(SSRs).
Check the regeneration RTD and tighten
if needed.
Check the heater fuses, and resistance
across each leg of the process heater.
Check the regeneration RTD and tighten
if needed.
Replace the return air RTD.
Check the heater fuses, and resistance
across each leg of the process heater.
Check the regeneration RTD and tighten
if needed.