Siemens GEAFOL Neo Operating Manual page 26

9. Maintenance
9.3 Frequently asked questions guidelines (chart)
S/N Question
Temperature controller
1
does not display
Temperature
controller three phase
temperature display
FOC or FCC
2
Three-phase
temperature display of
temperature controller
differs greatly
The temperature
controller cannot
3 communicate properly
with the monitoring
electric cable are arranged together, which causes the interference of the
device
there are high frequency vibrations during the excitation of the iron core,
4 Noise is abnormal
In the transformer load, equipment such as frequency converter produces
Cooling fan is not
5
running
Low side output
6
voltage is high or low
Transformer over-
7
temperature alarm, trip
Winding surface
8
High and low voltage transmission lines suffer from overvoltage impulse
discharge
Winding ablation and
9
blackening
24
Possible cause
Temperature controller power cord is not connected
It is internal failure of temperature controller, power interface of
temperature controller is energized, but panel indicator lamp is not on
Wrong or poor connection or loose connection of temperature sensor
Temperature sensor probe is damaged
Temperature sensor probe is not fully inserted into thermometer tube
(three-phase probe is inserted at different depths)
Cooling fan is damaged
Temperature sensor probe is damaged
Three-phase load of transformer is not balanced
Wrong address setting for temperature controller
The communication cable of the temperature controller and the strong
communication signal
Primary side voltage exceeds tapping rated voltage
The bus bar is not fixed well and there is resonance. The transformer is not
well fixed with the ground, and the resonance enclosure plate is not fixed
tightly, and there is resonance
There are unclamped free ends in the iron core or clamping parts, and
resulting in abnormal noise
Within the same power distribution room, multiple devices are placed
close together, causing wall reflections and noise overlapping
large harmonics in the system, which makes the core excitation uneven
and causes noise
Transformer is under overload operation state
Temperature does not reach fan start temperature value
Cooling fan is damaged
Grid input voltage is high or low
Transformer overload (overvoltage, over current) operation
Cooling of transformer fails
Severe stains (dust, etc.) on the surface of the winding
Short circuit on high and low voltage lines
There is insufficient distance between metal structure and winding
Upon the service life of the transformer and natural damage; poor heat
dissipation; long-term overload; short circuit of external wiring; system
overload; wrong cable connection; metal foreign body falling into the
cooling air duct of the winding; unscrewed torque of tap gear bolt; short
circuit fault inside the winding, etc.
Corrective measure
Measure whether the temperature controller power
interface is energized and required to reconnect the
power supply (85 ~ 250 V)
Contact Siemens After Sales Service Center to replace
with a new temperature controller
Check and press the temperature sensor wiring and
tighten it according to the auxiliary wire diagram on
the transformer certificate of conformity
Contact Siemens After Sales Service Center to replace
the temperature sensor
Check the position of the temperature probe and
place it correctly
Contact Siemens After Sales Service Center to replace
with a new cooling fan
Contact Siemens After Sales Service Center to replace
with a new temperature sensor
Check three-phase load and voltage, current
Please refer to the use manual for the temperature
controller
Properly lay out the cables
Disconnect the power of transformer and adjust tap
gear, refer to Item 8.1
Bus bar, enclosure board and transformer base are
well fixed
Check the fastening core and clamping piece and
press the free end tight with insulating material
Reasonably lay out equipment position in power
distribution room
Filter device is designed in low voltage system
Check the load and distribute the load reasonably
Refer to Item 7.1. 1 for factory temperature setting
value and setting method
Contact Siemens After Sales Service Center to replace
with a new cooling fan
Adjust the tap gear of transformer, refer to Item 8.1
Check transformer load
Check whether the cooling fan is working properly
and check whether the cooling air duct is blocked
Clean stains on windings, pads, etc.
Check high-voltage lines
Optimize system protection functions
Refer to 6.6 minimum insulation clearance
requirements
On-site inspection is required. Please contact Siemens
after-sales service center for such inspection.