User's Manual
ALPHA meter
IL42-4001S
4
Installation wiring
All available ALPHA meter forms are listed and separated with respect to the type of service being
metered. Use of Form 9S, 10S, and 10A (in 8S and 8A applications), and Form 16S (in Form 15S
application) are also shown. Form 14S and 14A applications are simply 4 wire WYE services and would
be metered by Form 16S and 16A. The more complicated wirings are shown using both PTs and CTs.
The socket ground is shown for safety considerations. The neutral-to-ground connection is shown for
example only. Actual neutral-to-ground connection should be performed within the operating utility's
standard practice.
Single phase meters
N
1
L
O
A
D
1
N
1
N
Form 1S
1 phase, 2 wire, self–contained
20E01
1
2
N
L
O
A
D
2
N
1
N
2
1
Form 2S
1 phase, 3 wire, self–contained
20E01
Form 3S
1 phase, 2 wire, 1 CT, no PTs
29A02
1
N
N
1
CIRCUIT
CLOSING
DEVICE
Form 3S
1 phase, 3 wire, 1 CT, no PTs
14I01
1
2
N
N
2
1
CIRCUIT
CLOSING
DEVICE
Form 4S
1 phase, 3 wire, 2 CTs, no PTs
29A02
1
2
N
N
2
1
CIRCUIT
CLOSING
DEVICE
Reduce CT ratio by ½