2
Using the MJ-XL Operator Panel and Controls
10
Siemens Power Transmission & Distribution, Inc.
2.7
Fuses
Power Fuse
This 4.0 Amp fuse protects the MJ-X
L
Control Panel circuit
and the tap changer motor circuit.
Sensing Fuse
This 0.4 Amp slow-blow fuse protects the MJ-X
L
Control
Panel sensing circuit.
External Power Source Protection Fuse
This 4.0 Amp fuse protects against the “hot” side of the
120 V external source being connected to the front panel
ground (white) binding post.
2.8
Terminal Strip Connections
Complete descriptions of all terminal contacts are
provided in Appendix K.
Terminal strips are located on the lower back side of the
MJ-X
L
Control Panel. These terminals can be used to pro-
vide access to certain microprocessor and other control
functions. Necessary jumpers are installed at the factory
and there is no need to add or change any of them unless
you need to access the electrical signals present there.
The terminal strips include four terminal pairs for VRC con-
trol and external inhibit function. The terminal strips
include the Current Circuit terminal pair.
Each terminal strip contact is screw type, to facilitate con-
nection and disconnection of external wiring.
Current Circuit Terminal Contacts
The nominal 200 mA secondary of the regulator current
transformer (CT) is routed through these terminals labeled
C and C2. This terminal pair is provided with a removable
shorting bar to accommodate auxiliary apparatus. These
terminals are shorted at the factory and must remain
shorted unless an appropriate external device is attached.
WARNING
Hazardous voltage will be present on
various control leads when regulator is
energized.
Could result in death or serious injury
including equipment damage from
contact with live line conductors.
To prevent:
Remove fuses before by-passing the
regulator and leave the fuses out while
the regulator is bypassed.
DANGER
Open CT secondary will result in high
voltage at CT terminals.
Will result in death or serious injury
including equipment damage.
To prevent:
Do not operate with CT secondary open.
Short circuit or apply burden at CT
secondary (C2-C) during operation.
Summary of Contents for MJ-XL
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