Voltage Reduction Device (Vrd); General Remarks; Safety Principle; Generator-Powered Operation - Fronius TransPocket 2500 Instructions De Service

Voltage Reduction Device (VRD)

General remarks

Voltage Reduction Device (VRD) is an optional safety device for voltage reduction. As far
as possible, VRD prevents output voltages at the current sockets that may pose a
danger to persons.

Safety principle

Fig.11 VRD is active
Fig.12 VRD is not active
Important! Within 0.3 seconds of end of welding:
-
-

Generator-powered operation

The power sources in the TP 2500 series are totally generator-compatible, provided that

Requirements

the maximum apparent power delivered by the generator is at least 14 kVA.
Fig.13 Mains voltage tolerance range
VRD is active once more
The output voltage is limited to 12 V once more
NOTE! The voltage delivered by the generator must NEVER violate the upper
and lower limits shown.
360 V~
Welding circuit resistance is greater than
the minimum human body resistance
(greater than or equal to 200 Ohm):
- VRD is active
- Open circuit voltage is limited to 12 V
(otherwise 90 V)
- There is no risk in unintentionally
touching both welding sockets at the
same time
Welding circuit resistance is less than the
minimum human body resistance (less
than 200 Ohm):
- VRD is inactive
- Output voltage not restricted in order
to ensure sufficient welding power
- Example: Welding start-up
400 V~
-10%
16
440 V~
+10%