Trimod Besta LTB002X Instrucciones De Servicio página 15

Microswitches type B have gold-plated contacts. At electrical values higher than normally used for in-
trinsically safe circuits or high voltage/power applications, the gold layer will be permanently damaged.
7. Maintenance
Level switches must be checked and cleaned regularly (min. 1x annually).
Procedure:
1. Cut off power supply before opening enclosure cover! Be aware of the danger of hazardous volt-
age!
2. Vent process vessel to atmosphere, if necessary lower liquid level. If the level switch is fitted to a
float chamber, isolate chamber by closing relevant valves and vent or drain as applicable.
3. Unbolt connection flange and remove level switch.
4. Check float for easy and free movement over its entire travel.
5. Remove any deposit of sludge, scale etc. Remove any metallic particles adhering to the float
magnet with putty or adhesive tape.
6. Floats with protective bellow (shroud): remove same and clean inside of any deposit.
7. Use stainless steel split (cotter) pins for replacement only.
8. Check correct function of switch with an acoustic circuit indicator while moving the float between
its two stop positions.
9. If necessary, replace flange gasket and O-rings and mount level switch again.
10. Energize power supply only when hinged cover is closed!
8. Malfunctioning and Troubleshooting
The fault descriptions and notes on the possible cause are based on the assumption that the compo-
nents have been correctly installed and connected.
Malfunctioning
Level switch does not
switch
Level switch does not
switch
Level switch does not
switch
Level switch does not
switch
9. Replacement of the switch module
Defective controller modules must be replaced with new, works-tested units. In order that the complete
type designation can be stamped on the type plate, the complete designation of the existing controller
must be specified at the time of ordering. If a complete identification of the controller is not possible,
then the manufacturer should be consulted before dispatching the complete device.
www.trimodbesta.com
Possible cause
No mains voltage
Float jammed, no full
deflection
Float damaged
Microswitch damaged
15 │ 46
Remedy
- Check mains voltage supply line.
- Loosen flange connection and remove the level
switch.
- Remove deposits and metal particles by means
of suitable and approved methods.
- Care must be taken to ensure that no mechani-
cal damage occurs as a result of the cleaning.
- Loosen flange connection and remove the level
switch.
- Remove the float and check for damage.
- If filled with medium, it is defective
► Replace float
- Function of switch module must be checked by
means of an acoustic continuity tester or similar
device.
- If defective ► Replace the switch module
LTB002X │ 2023/01