Fuse/Circuit Breaker Sizing Guidelines - Xantrex PROwatt 1750 Owner's Manual

Fuse/Circuit Breaker Sizing Guidelines

Because your batteries can produce thousands of amps, you need fuses or
circuit breakers that can safely withstand the short-circuit current they can
produce.
To select the correct fuse type and size:
1. Determine the total cold cranking amp rating for your battery(s). (The
cold cranking amp rating of each battery is displayed on the battery
case. If it is not, contact the battery manufacturer.) For example:
• If you are using one battery to power your inverter and its rating is
500, the total cold cranking amp rating is 500.
• If you are powering your inverter with two batteries, and each has a
rating of 500, the total cold cranking amp rating is 1750.
2. Once you have determined the total cold cranking amp rating of your
batteries, identify the corresponding Ampere Interrupting Capacity
(AIC) of the fuse or breaker required for your system by referring to
Table 3-2. (The AIC is the amount of battery short-circuit amperage
that the fuse can safely withstand.)
• If the Total Cold Cranking Amps indicate that the AIC needed is
2,700 amps or less, choose an ANL 250 fuse.
• If the Total Cold Cranking Amps indicate that the AIC needed is up
to 20,000 amps or if you require a "code fuse", choose a Class T
1
250 A fuse.
Table 3-2 Cold Cranking Amps / Ampere Interrupting Capacity
Total Cold Cranking
Amps
650 or less
651–1100
over 1100
1.The figures in
ABYC (American Boat and Yacht Council).
Ampere Interrupting Capacity
Table 3-2 are based on standards developed by the
Connecting DC Cables
(AIC)
1500
3000
5000
3–13