Effective 7/1/2003
Page 34
I.L. 70C1037H04
Figure A.1 Typical Zone Interlocking
Figure A.2 Typical Zone Interlocking Connections with Two Main Breakers (M1, M2) and a Tie Breaker (T)
3200A
Main
Zone 1
Zone 2
Zone 3
2
200A
1
1600A
3
Branch
0.3 Sec
400A
0.1 Sec
100A
0.5 Sec
1200A
Feeder
Zone
1
Zone
2
Zone
3
C
C
C
ZO
ZO
ZO
ZI
ZI
ZI
Notes:
A1:
A2:
A3:
A4:
Wiring to be twisted pair of AWG #14 to #20. Route
Zone Interlocking wiring separate from power conductors.
DO NOT GROUND any Zone Interlocking wiring.
The maximum distance between two farthest breakers
on different zones (from the ZO downstream to ZI upstream
terminals) is 250 feet (76m).
A maximum of 20 breakers may be contained in parallel
in one zone.
Provide a self interlocking jumper (on Zone 3) if
coordination is desired with other downstream breakers
not providing the zone interlock feature.
2
C
ZO
ZI
Legend
= Common (ungrounded) - B7 Contact
= Zone Out Output Signal - B9 Contact
to Higher Level Zone
= Zone In Input Signal - B8 Contact
from Lower Level Zone
= Fault at Location 2
See Note A4
