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Current Limiter size
- Thread starter avi8tor50
- Start date
hevansrv7a
Well Known Member
Comant doubler
Simply because the belly skin appeared to be .040, I used .040 for the doubler. Open to criticism, but it seemed reasonable at the time.avi8tor50 said:
gmcjetpilot
Well Known Member
Current protection: Fuse or CB?
Current limiter? hummmmm drawing a blank? Limit what current? Are you talking Fuse or CB? There is no current limiter in the classic sense, but it does protect the wire from TOO much current.
In general if current gets to high for a cuircuit (ie ground or short) you protect the wire with a fuse or circuit breaker (CB) at the power source. With out it the wire would glow red, melt the insulation and be a fire hazard. The size of the wire must be large enough to handle the max operational current and also be more than the protection (fuse/CB). Most find the most they need is about 18-20 discrete fuses or CB's, but you can by with less if you GANG on each fuse, like in you house, where one CB handles many circuits.
Are you talking about OVER VOLTAGE?
If you are talking about over voltage (OV) protection that usually involves
something to do with the source it self, in our case the source is either battery or alternator. Since the battery is unlikely to go "over voltage" we are talking alternator. That is a hot topic. If you search OV or over-voltage you can read enough to have your eyes bleed.
Ditto on 0.040 belly skin, 0.040 doubler. If you can pick up a floor rib (more correctly an intercostal) with a flange the better.avi8tor50 said:
Current limiter? hummmmm drawing a blank? Limit what current? Are you talking Fuse or CB? There is no current limiter in the classic sense, but it does protect the wire from TOO much current.
In general if current gets to high for a cuircuit (ie ground or short) you protect the wire with a fuse or circuit breaker (CB) at the power source. With out it the wire would glow red, melt the insulation and be a fire hazard. The size of the wire must be large enough to handle the max operational current and also be more than the protection (fuse/CB). Most find the most they need is about 18-20 discrete fuses or CB's, but you can by with less if you GANG on each fuse, like in you house, where one CB handles many circuits.
Are you talking about OVER VOLTAGE?
If you are talking about over voltage (OV) protection that usually involves
something to do with the source it self, in our case the source is either battery or alternator. Since the battery is unlikely to go "over voltage" we are talking alternator. That is a hot topic. If you search OV or over-voltage you can read enough to have your eyes bleed.
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Actually, I have seen several builders who use a current limiter between the alternator and the main bus. B&C sells them and my understanding is that Bob Nuckolls is leaning more to the current limiter than a large fuse between the alternator and the main bus. The current limiters that B&C sell come in several different amp strenghts. Was just wondering what others have used. You might want to check out his site.
gmcjetpilot
Well Known Member
OK I am stumped
I think you are talking about a big FUSE? That fuse is sized at or slightly above the max output potential of the alternator. So you have a 45 amp alternator, 50 or 60 amp fuse will work. Again current limiter? I think fuse.
If not, you are talking about a OV relay. I would not recommend that on ANY ND alternator. Van does not recommend or warranty alternators with OV relays, but again check the archives and search on OV or over voltage or overvoltage.
I know Bob Nuckolls swears by his OV relay, but it has been the death of many ND alternators. The fact is ND alternators are very reliable and DON'T go super nova OV like Bob scares people into thinking. The cure is worse than the ill. In fact an OV relay is heavy and adds more connections and chance for failure. Trust me or not, call Van. Bob N's answer is Van is ignorant and Bob. Of course Bob said that before he knew all the problems Van has seen with builders who follow his wiring, specifically the OV relay. Van also sells 10 alternators or more a month for a decade or more; do the math, they hear about all the problems and the common thread in many was Bobs OV relay and "crow bar".
My OV opinion is for most folks no additional OV protection is needed on the ND (NipponDenso) alternators with internal voltage regulation (I-VR). They are somewhat self protected or fail in a safe or benign way. There is the "Plane Power" brand of alternator, which is a modified ND with an extra OV module or protection device. It senses an OV and turns the alternator off automatically. The few people that have experienced OV, with a I-VR ND alternator have found it to be mild. Mild means target voltage should be 14.3-14.6 volts, and the voltage wonders up to 15 or 16 volts. In general you can manually turn the alternator off your self in that unlikely event. 16 volts should not damage modern avionics which are designed to work from 10-30 volts, and tolerate a 60 volt Spike. Of course you don't want to fly around for a long time with +15 volts as it will damage the battery. However as you know if you voltage is high you can usually get it down by lowering RPM and adding more load, like landing lights.
Good luck
Have no idea, never heard of a Current Limiter between the alt and the buss, but than you answered you question, you need one?avi8tor50 said:
I think you are talking about a big FUSE? That fuse is sized at or slightly above the max output potential of the alternator. So you have a 45 amp alternator, 50 or 60 amp fuse will work. Again current limiter? I think fuse.
If not, you are talking about a OV relay. I would not recommend that on ANY ND alternator. Van does not recommend or warranty alternators with OV relays, but again check the archives and search on OV or over voltage or overvoltage.
I know Bob Nuckolls swears by his OV relay, but it has been the death of many ND alternators. The fact is ND alternators are very reliable and DON'T go super nova OV like Bob scares people into thinking. The cure is worse than the ill. In fact an OV relay is heavy and adds more connections and chance for failure. Trust me or not, call Van. Bob N's answer is Van is ignorant and Bob. Of course Bob said that before he knew all the problems Van has seen with builders who follow his wiring, specifically the OV relay. Van also sells 10 alternators or more a month for a decade or more; do the math, they hear about all the problems and the common thread in many was Bobs OV relay and "crow bar".
My OV opinion is for most folks no additional OV protection is needed on the ND (NipponDenso) alternators with internal voltage regulation (I-VR). They are somewhat self protected or fail in a safe or benign way. There is the "Plane Power" brand of alternator, which is a modified ND with an extra OV module or protection device. It senses an OV and turns the alternator off automatically. The few people that have experienced OV, with a I-VR ND alternator have found it to be mild. Mild means target voltage should be 14.3-14.6 volts, and the voltage wonders up to 15 or 16 volts. In general you can manually turn the alternator off your self in that unlikely event. 16 volts should not damage modern avionics which are designed to work from 10-30 volts, and tolerate a 60 volt Spike. Of course you don't want to fly around for a long time with +15 volts as it will damage the battery. However as you know if you voltage is high you can usually get it down by lowering RPM and adding more load, like landing lights.
Good luck
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Just checked Bob's site again. Yes the current limiter is similar to a big fuse-just has a few different characteristics. He is recommending that it be substituted for the "big fuse" the he previously recommended betwee the b lead of the alterhnator and the starter contactor. And it is called a "current limiter." I will be using a Plane Power 60 amp alternator.
Anway, for those of you out there that see this discussion, the question stands: What size ANL current limiters are you using?
I was thinking about 70-80 amp if that size is available since Bob suggests one abouyt 20% above the alternator output.
Anway, for those of you out there that see this discussion, the question stands: What size ANL current limiters are you using?
I was thinking about 70-80 amp if that size is available since Bob suggests one abouyt 20% above the alternator output.
az_gila
Well Known Member
Standard values here
Well this TX Avionics place seems to follow Bob N's theories...
This link gives the ANL standard sizes...
http://www.dallasavionics.com/cgi-b...install_supplies&man=limiters&subcat=limiters
80 Amps would bethe closest to the one you want...
IIRC Home Depot (Aviation electrical section) also has them...
gil in Tucson
avi8tor50 said:
Well this TX Avionics place seems to follow Bob N's theories...
This link gives the ANL standard sizes...
http://www.dallasavionics.com/cgi-b...install_supplies&man=limiters&subcat=limiters
80 Amps would bethe closest to the one you want...
IIRC Home Depot (Aviation electrical section) also has them...
gil in Tucson
Paul Eastham
Well Known Member
How do you or Van's know that these failures aren't just due to shoddy alternators rather than the regulator/OV?gmcjetpilot said:
A whopping 9 ounces according to their web site...?gmcjetpilot said:
William Slaughter
Well Known Member
You should be ok, Rick. From what I've read on the Matronics Aeroelectric List, the ANL current limiters are very, very "slow blow" and can be sized right at the rated output of your alternator. I'm putting on the same combination of alternator and ANL limiter you have.
tx_jayhawk
Well Known Member
Home Depot?
Someone mentioned ANL fuses were available at Home Depot? Can anyone point me to what section in the store (I love "local" aviation supplies)?
THanks,
Scott
Someone mentioned ANL fuses were available at Home Depot? Can anyone point me to what section in the store (I love "local" aviation supplies)?
THanks,
Scott
