Siemens 3VA1 100 A, Manual

Page: 211 / 532

Accessories
4.4 Plug-in and draw-out technology
3VA molded case circuit breakers
Manual, 04/2015, A5E03603177010-02
211
Terminal covers
As described above, two screw-mounted terminal covers are included in the plug-in socket
complete kit and the plug-in socket conversion kit. These feature molded grips to ease
withdrawal of the molded case circuit breaker from its socket. Since it requires significant
force to remove a molded case circuit breaker from its socket, the plug-in terminal covers are
bolted to the contact unit.
If the termination area of the plug-in socket needs to be protected by terminal covers, a
variety of models of terminal cover are available to order as options for this purpose.
Autotrip plunger
An autotrip plunger is supplied as standard with every complete kit and every conversion kit
for converting a 3VA molded case circuit breaker to plug-in technology. The plunger
performs safety functions in operation.
When a 3VA molded case circuit breaker is converted to a 3VA plug-in unit, this plunger is
installed from the rear of the device and latched. The plunger performs safety functions in
operation. It prevents the molded case circuit breaker from being switched to the ON position
if the breaker is not correctly bolted to the socket. For further information, see also section
"Signal 'Plug-in unit - MCCB correctly bolted to plug-in socket'" in chapter Position signaling
switches (Page 225).
WARNING
Make sure that the autotrip plunger is correctly installed
The molded case circuit breaker cannot be safely moved into or out of the socket without
an autotrip plunger. Moving it into or out of the socket when the main contacts are closed
(breaker position ON) can cause arcs to form between contacts and result in irreparable
damage to the circuit breaker or the electrical installation, and possibly cause physical
injury to personnel.
Once installed, the autotrip plunger cannot be dismantled again!
Note the color coding and labels for the autotrip plunger:
•
Plug-in technology: Black, labeled "Plug-in"
• Draw-out technology: Grey, labeled "Draw-out"