Template · Service and panels

400A service with two 200A panels single line diagram

Class 320 meter socket feeding two main panels. Use this for a 400A residential service built from a class 320 meter socket and two 200A main panels.

A free template with typical ratings, conductor callouts and general notes. Open it, change what differs on your job, fill in the title block and export a PDF.

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400A service with two 200A panels single line diagram: class 320 meter socket feeding two main panels. — 400A service with two 200A panels. 14 devices on an 11 × 17 in sheet with a title block and notes column.

What the reviewer checks on this drawing

The reviewer checks that each main breaker is a service disconnect, grouped and labelled; the grounding electrode conductor size; and a main bonding jumper in each service disconnect enclosure.

What the drawing shows

Every device on the sheet, in the order power reaches it.

Symbol	Label	Rating or detail	Conductors feeding it
Utility source	Utility service	120/240V 1φ 3W
Meter	Utility meter	320A socket (CL320)	Service conductors, per utility
Circuit breaker	200A 2P	Main A
Panel	Panel A	200A bus · 120/240V
Circuit breaker	Existing	House loads
Load	Existing loads
Circuit breaker	200A 2P	Main B
Panel	Panel B	200A bus · 120/240V
Circuit breaker	60A 2P
EV charger	Level 2 EVSE	48A
Circuit breaker	50A 2P
Load	Heat pump
Circuit breaker	40A 2P
Load	Range

Notes on the sheet

Each main breaker is a service disconnect. Group the disconnects and label each one.
Grounding electrode conductor sized for the service entrance conductors.
Main bonding jumper installed in each service disconnect enclosure.

Diagram is schematic and not to scale. Field-verify existing equipment ratings. Ratings and conductor sizes shown are typical. Confirm against the adopted code, the equipment listing and a load calculation before installation. Code references are to the 2023 NEC and the 2024 Canadian Electrical Code: see references and editions.