alternator question
If an alternator is rated 200 amps,why cant they tell you at what RPM this rating is good.At idle,650rpm, or at cruising,1950 RPM. If you get a diesel rig,there is a high idle setting to get more amp...
Forum Discussion
Hi,
My understanding of "high idle" on diesel is that it is more about sufficient oil pressure to prevent damage to the motor, than greater output from the alternator.
The common garden variety alternators are rated at their peak output. This is a far higher number than the continuous duty output. I derate my 130 amp by 1/3 and call it about 90 amps maximum. Even at that level I sometimes see the voltage start to drop which is a BIG signal to lower the load. Ignore the signals and soon there will be a bill to pay for a new alternator.
If the voltage hits 12.9 I lower the load on the electrical system right away.
My understanding of "high idle" on diesel is that it is more about sufficient oil pressure to prevent damage to the motor, than greater output from the alternator.
The common garden variety alternators are rated at their peak output. This is a far higher number than the continuous duty output. I derate my 130 amp by 1/3 and call it about 90 amps maximum. Even at that level I sometimes see the voltage start to drop which is a BIG signal to lower the load. Ignore the signals and soon there will be a bill to pay for a new alternator.
If the voltage hits 12.9 I lower the load on the electrical system right away.
RWDIII wrote:
If an alternator is rated 200 amps,why cant they tell you at what RPM this rating is good.At idle,650rpm, or at cruising,1950 RPM.
If you get a diesel rig,there is a high idle setting to get more amps
but is not available for gas rigs,Ford,.
When I got my truck serviced at the dealer,I asked and all I got was a stare LIKE I was speaking Chinese. :h
