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• DOK-POWER*-TVD*1.3****-ANW1-EN-E1,44 • 02.97
3. Electrical Connections
3.5. Fuse protection for direct mains connection
Protection for the mains input to the power section of the TVD 1.3 for direct
connection to the mains can be effected by power circuit-breaker or with
fusible links, utilization category gL.
The fuse rating may not exceed 35 A.
The following recommendations are valid when circuit breakers are used for
direct connection to mains.
If fuses are used, then fuses with utilization category gL can be used. Semi-
conductor fuses are not required. Select the fuses in terms of the mains
current.
Maximum fusing
DC bus
Connected Mains current
Power circuit
Adjust.
Cross sect. of
contin.
load
at
breaker
current connected load
power
at380V
380V 480V
Siemens type
lead
3)
7,5 kW
10 kVA
15 A 13.4 A 3VU1300-.MN00
1)
15 A
2.5 mm
2
15 kW
20 kVA
30 A 26.8 A 3VU1600-.MP00
2)
30 A
6 mm
2
1)
Max. back-up fuse as per manufacturer: 80 A (gL) for supply voltages up to 500 V
2)
Max. back-up fuse as per manufacturer: 200 A (gL) for supply voltages up to 500 V
3)
Lead cross section per EN60204 - installation type B1 - without taking correction factor into
account
Fig. 3.7: Recommended fusing for the mains supply conductors
3.6. Mains supply earthing requirements
The TVD 1.3 can be connected to a grounded wye or delta system without
potential isolation.
For ungrounded three-phase mains supplies (IT mains) there exists the
increased danger that overvoltages that are not permissible can occur
between the phases and the housing. The TVD 1.3 can be protected against
overvoltages
• if it is connected via an isolation transformer
(connect the neutral point of the transformer to the TVD with a PE rail) or
• if the machine is protected by overvoltage detector.
Connecting the TVD 1.3 via an isolation transformer offers the best protection
against overvoltage and the greatest possible operating safety.
Earthed three-phase
mains
Unearthed three-
phase mains
I
N
=
P
DC
U
N
•
25, 5
I
N
= mains current in A
P
DC
= DC bus continuous power in W
U
N
= mains voltage in V
