3.7 Instructions For Testing The Scr - ABB PSTX370 Service Manual

3.7 Instructions for testing the SCR
IMPORTANT NOTE
Only perform the SCR-test if the
Softstarter displays one of the following
faults: "Short circuit thyristor fault" or
"Open circuit thyristor fault"
Replace SCR if the result of the test
shows under 1 Mohm.
WARNING. HAZARDOUS VOLTAGE
Always make sure that the power supply is
switched off before doing maintenance on the
3
Softstarter.
WARNING
When performing maintenance on the Softstarter,
an antistatic strap must be used. The antistatic
strap should be worn on the wrist, and be
connected to an electrical ground, to prevent
electrostatic discharge (ESD) damage to the
Softstarter.
WARNING
The life span of electronics can be affected by
damage caused by electrostatic discharge. This
can happen if a charged tool or person touches a
component. Therefore it is very important that all
tools and personnel are discharged by touching
an earthed point before the PCBA or any of the
components are touched. It is equally important to
discharge the package with the new component
before opening it.
A person walking on a carpet can be charged with
up to fifteen thousand volt (15000V). Compare
this with the fact that some sensitive components
can be destroyed when discharged on a much
lower level (about 100V). We kindly ask you to pay
notice to this, as this is a vital point in order to
ensure the life span and function of the product.
Tools:
• Torx 15 for removing the front cover
• Torx 20 for removing the front cover
• Long-nose plier for removing the cables from the
PCBA
• Megger to set on 500V
Service PSTX210...370 | Service Manual |
40 1SFC13105M0201