Maxim Integrated 78M6631 Evaluation Board - Manual (Page 10)

78M6631 Evaluation Board User Manual UM_6631_077
10 Rev 1
2.4 3-Phase System Connection
The 78M6631 Evaluation board supports both Wye (3-phase 4-wire) and Delta (3-phase, 3 wires)
configurations. The current transformers are not provided with the evaluation board and must be selected
by the customer. A burden resistor (12.4 Ω – value dependent on CT) can be connected on each phase
through dedicated jumpers. Particular attention must be placed in configuring the burden resistors as the
current transformers can generate high voltage if no burden resistor is present (or if its value is too high).
Figure 2 and 3 shows a connection diagram using external burden resistor, in this case the external
burden resistor can replace the on-board or used in parallel.
A
Neutral
B
C
LOAD A
LOAD B
LOAD C
A
Neutral
B
C
J15
(VA)
J17
(VB)
J19
(VC)
J14
(V3P3)
J13
(ICN)
J10
(ICP)
J9
(IBN)
J5
(IBP)
J4
(IAN)
J1
(IAP)
External Equipment
78M6631 Evaluation Board
Optional
Optional
Optional
Figure 2: 78M6631 Evaluation Board Application Diagram (Wye 3-phase 4-wires)
J15
(VA)
J17
(VB)
J19
(VC)
J14
(V3P3)
J13
(ICN)
J10
(ICP)
J9
(IBN)
J5
(IBP)
J4
(IAN)
J1
(IAP)
A
B
C
LOAD A-C
A
B
C
LOAD A-B
LOAD B-C
External Equipment
78M6631 Evaluation Board
Optional
Optional
Figure 3: 78M6631 Evaluation Board Application Diagram (Delta 3-phase 3-wires)