Technical Brief for Installation of Consumption Monitoring

Installing Consumption CTs
 2016 Enphase Energy Inc. All rights reserved. January 2016
10
Example Calculations for a Service Panel
Suppose a service panel contains the following line conductors:
Circuit Description
Breaker
Ampacity
Line
Conductors
Conductor Type
and Size
L1 – Black
Conductor
Area
L2 – Red
Conductor
Area
Electric heating
50
1 and 2
2 - #6 THWN
0.0507in
2
0.0507in
2
Oven
50
1 and 2
2 - #6 THWN
0.0507in
2
0.0507in
2
Stove top
40
1 and 2
2 - #8 THWN
0.0366in
2
0.0366in
2
Air conditioner
30
1 and 2
2 - #10 THWN
0.0211in
2
0.0211in
2
Electric dryer
30
1 and 2
2 - #10 THWN
0.0211in
2
0.0211in
2
Pool pump
30
1 and 2
2 - #10 THWN
0.0211in
2
0.0211in
2
Pool filter
30
1 and 2
2 - #10 THWN
0.0211in
2
0.0211in
2
Hot tub
40
1 and 2
2 - #8 THWN
0.0366in
2
0.0366in
2
Lights 1
20
1
1 - #12 THWN
0.0133in
2
Lights 2
20
2
1 - #12 THWN
0.0133in
2
Lights 3
20
1
1 - #12 THWN
0.0133in
2
Lights 4
20
2
1 - #12 THWN
0.0133in
2
Lights 5
20
1
1 - #12 THWN
0.0133in
2
Lights 6
20
2
1 - #12 THWN
0.0133in
2
Receptacles 1
20
1
1 - #12 THWN
0.0133in
2
Receptacles 2
20
2
1 - #12 THWN
0.0133in
2
Receptacles 3
20
1
1 - #12 THWN
0.0133in
2
Receptacles 4
20
2
1 - #12 THWN
0.0133in
2
Receptacles 5
20
1
1 - #12 THWN
0.0133in
2
Receptacles 6
20
2
1 - #12 THWN
0.0133in
2
Receptacles 7
20
1
1 - #12 THWN
0.0133in
2
Receptacles 8
20
2
1 - #12 THWN
0.0133in
2
Total
0.3521in
2
0.3521in
2
• The sum of the cross-sectional areas of these conductors could fit into a single set of consumption
CTs.
• A consumption CT filled to 60% of the cross-sectional area can accommodate 0.484in
2
of
conductors.
• The sum of these homes conductors is 0.3521in
2
.