BCD.00617 Rev AB,16-Nov-2015

Page 4 of 15

MELCHER

The Power Partners.

Accessories Data Sheet

Backplanes BPD, BPF for T Series

L

LT

3

X1

L1

L2

L3

N

LT

2

LT

1

N

Y

YY

04017

Phase to Phase Configuration

With standard back plane version (Y-configuration)

For LT models exclusively

The layout of the standard back planes also allows phase to

phase connection at low mains voltage 208 V, e.g. USA, pro-

viding full output power from the LT units. In such cases one of

the two input lines (L1 or L2) should be connected to the N-

terminal at the AC input connector instead of the neutral line.

The neutral line is not connected. For safety reasons an

external fuse should be fitted in each input line. Connection to

the ground is mandatory.

Fig. 5

Phase to phase configuration L1, L2

120/208 VAC (e.g. USA): LT models only.

Not applicable for UT models.

Mains Input Section

Connection to the Mains

Connection to the mains shall be made via the 6-pole screw

terminal connector (X1), located on the right hand side of the

back plane (view from the rear).

For single phase operation the terminals (L1, L2 and L3) at

the female connector X1 should be connected together. The T

Series has two AC input voltage ranges. The LT units are

optimized for the 230 V mains, the UT units for the

120 V mains; see also the T Series data sheet on our website.

Single-phase/3-phase (Y) Configuration

Standard back plane version (Y-configuration)

The layout of the standard back planes allows operation of the

system either in single phase or in 3-phase (Y) configuration.

In both configurations each T unit on the back plane is

connected between its defined phase and neutral. For single

phase operation the AC-input terminals (L1, L2 and L3)

should be connected together at the female connector. Con-

nections to neutral and to ground are mandatory. (See also

fig.: Single phase configuration as well as fig.: 3-phase (Y)

configuration.) Equal load distribution on the input lines at 3-

phase configuration will compensate the low frequency ripple

at the output to zero.

Fig. 3

Single phase configuration L, N

230 VAC: LT models

Fig. 4

3-phase (Y) configuration L1, L2, L3, N

230/400 VAC:

LT models

120/208 VAC:

1

Reduced output power with LT models

L1

LT/UT

3

X1

L1

L2

L3

N

LT/UT

2

LT/UT

1

N

L2

L3

Y

Y

Y

04018

Table 2: Mains input arrangement

Mains voltage

Single phase

3-phase (Y)

Phase - phase (

3-phase (

Phase-Earth/Phase-Phase

L, N,

L1, L2, L3, N,

L1, L2,

L1, L2, L3,

230/400 V

LT models

LT models

Not allowed

Not allowed

120/208 V

(LT models)

LT models

LT models only

With special back plane

UT models

UT models

External fuses required

BPF 1037 and

LT models only

L1

LT

3

X1

L1

L2

L3

N

LT

2

LT

1

L2

Y

Y

Y

04019