Surge
Arrester
Recloser
Head Ground
Surge
Arrester
Transformer
Surge
Arrester
Arrester Ground
Recloser
Pole
Supply
Voltage
Pole
Ground
Form 4D
Control
Customer Ground Connection
At External Lug
NEU
AC
GND
NEU
AC
Input
Terminal
Block
Control
Cable
AC
NEUTRAL
Form 4D Control
Supply Voltage
Transformer
ELECTRICAL CONNECTIONS
Line to Neutral connected transformer
Input Terminal
Block TB1
External
Ground Lug
Figure 12. Recommended grounding method for the Form 4D pole-mount recloser control installed on 4-wire
multi-grounded, with local supply voltage transformer
WARNING
Hazardous voltage. Recloser and control must
be solidly grounded. Follow all locally approved
procedures and safety practices when grounding this
equipment. Improper grounding can result in contact
with high voltage, which will cause death or severe
personal injury.
G115.1
Grounding with a remote supply voltage
transformer; 4-wire multi-grounded
Installation of a Form 4D pole-mount recloser control with a
remote supply voltage transformer must include the following:
Protection of the recloser bushings and the supplying
transformer with lightning arresters.
Grounding of the recloser head and tank.
Grounding of the transformer tank.
Grounding of the control cabinet.
Grounding of the SCADA equipment.
IMPORTANT
In pole-mounted applications, a ground connection
must be made between the recloser, transformer,
recloser control, and SCADA equipment for proper
protection of the equipment. The pole ground must
be sized per local utility practices to minimize the
impedance between the recloser and the control.
IMPORTANT
All external inputs to the Form 4D recloser control must be
routed within 8 inches of their corresponding ground. During
a surge, a potential of approximately 1.5 kV per foot can
develop in the conductors. Differences between conductor
and ground path lengths can add additional stress to the
control components in the event of a power surge.
IMPORTANT
Distance between transformer and recloser should be
one pole span or less.
16 OPERATION INSTRUCTIONS MN280049EN September 2017
Form 4D Microprocessor-based pole-mount recloser control installation and operation instructions