Calculating Fuse/Circuit Breaker Size - Xantrex 1200, 1750 Owner's Manual

Installation

Calculating Fuse/Circuit Breaker Size

Because your batteries can provide thousands of amps, you need fuses or
circuit breakers that can safely withstand the short-circuit current that the
batteries can produce.
To select the correct fuse type and size:
1. Determine the total cold cranking amp rating for your batteries. (The
Note
(CCA) rating is the sum of the CCA ratings of all of the batteries
connected in parallel.
2. Once you have determined the total cold cranking amp rating of your
Table 3-5
3–12
cold cranking amp (CCA) rating of each battery is displayed on the
battery case. If it is not, contact the battery manufacturer to determine
the CCA rating of your particular batteries.) For example:
• If you are using one battery to power your inverter and its cold
cranking amp rating is 500 CCA, the total cold cranking amp rating
is 500 CCA.
• If you are powering your inverter with two batteries connected in
parallel, and each battery has a cold cranking amp rating of 500
CCA, the total cold cranking amp rating is 1000 CCA.
: For batteries connected in parallel, the total cold cranking amp
batteries, identify the corresponding Ampere Interrupting Capacity
(AIC) of the fuse or breaker required for your system by referring to
Table 3-5. (The AIC is the amount of battery short-circuit amperage
that the fuse can safely withstand.)
Cold Cranking Amps/ Ampere Interrupting Capacity
Total Cold Cranking
Amps
650 or less
651–1100
over 1100
1. The figures in Table 3-5
ABYC (American Boat and Yacht Council).
• If the Total Cold Cranking Amps indicate that the AIC needed is
2,700 amps or less, choose an ANL 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 fuse.
Ampere Interrupting Capacity
(AIC)
1500
3000
5000
are based on standards developed by the
1