There are four basic types of manual transfer switches available
for connecting a backup power source or generator to a building wiring
system. With each there are advantages and limitations. Use the
table below to help determine which is best suited to your application.
Installation Arrangements
(click images to enlarge)
Maximum number of branch
circuits
4, 6, 8 or 10 branch
circuits
Switches 1 main circuit,
as many branch circuits that can fit in downstream panel
6 to 16 branch circuits
depending on model
36 branch circuits
Maximum rating of each
branch circuit
15A or 20A
(Q-series 30A)
200A, 400A or larger main,
branch circuit rating limited only by panel (usually 100A max)
varies depending on model,
some limited to 30A, others can accommodate up to 100A
100A
Individual control of each
circuit allowing some to operate on generator and others on utility?
Yes
No
No
No
Generator Meters?
Included on most models
Included on some models
Included on most models
Included on most models
Branch breakers freed up in
existing load center panel?
No
No
Yes
---
Additional double-pole
branch breaker required in existing load center panel?
No
No
Yes
(not included)
---
Ease of installation?
Easy
Difficult
Medium
Very Difficult
(unless new construction)
Installation Remarks
- connect flex conduit to
spare knockout
- disconnect wire from
each branch breaker
- connect to wire from
switch
- insert other switch wire
into branch breaker
- pull electric meter if no
disconnect at meter
- break main cable
- replace part of main
cable if too short
- mount and connect
switch
- purchase double-pole
branch breaker
- connect flex conduit to
spare knockout
- install branch breaker
and connect feed to sw.
- disconnect wire from
each branch breaker
- connect to wire from
switch
- disconnect all wiring
from existing panel
- remove existing panel
- mount new transfer
panel
- purchase and install all
branch breakers
- reconnect main supply
cable
- reconnect all branch
circuits
