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GARMIN GTR-225A - Current Draw & CB value

lucaperazzolli

lucaperazzolli

Well Known Member
Hi,

I'm installing the GTR-225A and I've an electrical question.

Why the manual says that the Maximum current draw is 4.2 Amp and the same manual request a CB of 10 Amp ?

:confused:
 
4.2A is just the Com side. Nav can draw another 1.2Aa.

Maybe a 7.5 CB would work. I'll have a look at my installation to see what was used.
 
Mark Albery said:
4.2A is just the Com side. Nav can draw another 1.2Aa.

Maybe a 7.5 CB would work. I'll have a look at my installation to see what was used.
Click to expand...

Good point of view Mark, thanks.

But 225A is only COM and 4.2 Amp is only for COMM connector, and for that connector the drawing says 10Amp CB with 18AWG.

ps: love your crossing the pond story ;)
 
lucaperazzolli said:
Hi,

Why the manual says that the Maximum current draw is 4.2 Amp and the same manual request a CB of 10 Amp ?

:confused:
Click to expand...

Probably because they specified 20 ga wire for power and 10 amps is the proper CB for a 20 ga wire. CB's protect the wire, not the device. If they are sized too close to the equip draw, you can get nuisance trips. I would assume garmin put a fast blow fuse in the device for protection.

Larry
 
lr172 said:
Probably because they specified 20 ga wire for power and 10 amps is the proper CB for a 20 ga wire. CB's protect the wire, not the device. If they are sized too close to the equip draw, you can get nuisance trips. I would assume garmin put a fast blow fuse in the device for protection.

Larry
Click to expand...

Thanks Larry, another interesting point of view.

the drawing calls for an 18 AWG and looking @ AC 43.13-1b (par11-47/Page 11-15, Table 11-3) the CB for a 18 Awg is 10 Amp value.

Problem solved ?
 
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