Chapter 10 Troubleshooting - Thermo Scientific BF51841C Operation Manual

Troubleshooting
Problem
Controller reads P.Er.
Controller reads b.o
Controller reads ooo.
Controller reads UUU.
Controller reads Err
The controller displays do
not illuminate.
Thermo Scientific
Table 5. Controller Troubleshooting
Probable Causes
Abnormal parameter value
Input burnout
PV exceed effective range
PV is below effective
range
Probable hardware failure
The furnace Is not con-
nected to the power
Main switch is defective
Fuse(s) Blown
Solution
Check controller parameter of settings
and reset to proper values
Check the sensor wiring, replace sen-
sor if necessary
Check the input type and range set-
tings and correct them
Check the input type and range set-
tings and correct them.
Call Service for controller repair
Check furnace connection to power
source
Replace power switch or controller
Replace fuse(s) and verify power con-
nections
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