Landing Light CB

(COUGARNFW)
shared these priceless pearls of wisdom:

-Nobody looks it up. The 4522 lamp is usually used in a swing-down lamp. The
-swing down lamp has a motor to drive the lamp up or down.

Yes, well, when you look it up, you might want to use the right number. The
original poster said 4552, not 4522. If you had a clue about things, you would
know that no 172 ever made had a swing-lamp setup. That died with the C-170
series. Google on 4552 and see your error.


-
-The lamp is 12 volt, 250 watt, something the guesser at 9 amps (if for a 24
-volt plane) would have realized if the system voltage of the plane had been
-given, so the current draw for the lamp along is a nominal 20 amps.

No, the lamp is 28 volt, 250 watt, which calculates to a skosh below 9 amps.
The guesser didn't guess, he calculated.


-
-If the motor circuit is not opened by the switch/relay built into the light,
-the combination of the lamp current and the motor current will pop the breaker
-every time, in a short time.

There is no motor.

-
-Yes, check the amps with a current meter, and please do not let the motor run
-long in the test or it will burn out.

a. There is no motor.

b. If you check the current with an ammeter (sorry, John), you will blow the
fuse in the ammeter when the failure mode occurs. As somebody who knew what
they were saying commented, the best way is with a second lamp of the same
rating in series with the wire right at the breaker. Under "normal" conditions,
both lamps will light equally bright. Jiggle/wiggle/tap/thump the wire along
its whole length, and when the wing mounted light goes dark and the test light
brightens up, you've found the location of the sharp edge that is cutting
through the wire's insulation.

Having said that, in general it is easier to pull the old wire out and pull a
new wire into place, being sure that when you pull the new wire that it doesn't
go over the same sharp edge that killed the old wire. Yes, this is called
shotgun troubleshooting, but in a situation like this it can result in reduced
labor costs and headscratching to find the exact point along the wire where it
is being inadvertently grounded.

No, a loose ground AT THE LAMP will cause the wire and aluminum at the lamp to
get hot, but it won't pop the breaker. However, a loose or corroded connection
at the BREAKER will cause the breaker to heat up (I-squared R loss) and pop.
You might check the connections at the breaker before you go off on a tangent.

Jim
Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

I think he needs to give me his Avcon conversion for our tried and true
Cont. 0-300D... I'll even throw in a Q-Beam... ;-)

That would be the sweetest deal you have ever got. I would rather not have a
landing light and keep my 180 Hp Lycoming with constant speed prop.
Hank

Hankal wrote:

I think he needs to give me his Avcon conversion for our tried and true
Cont. 0-300D... I'll even throw in a Q-Beam... ;-)

That would be the sweetest deal you have ever got. I would rather not have a
landing light and keep my 180 Hp Lycoming with constant speed prop.

Thanks Hank, lemme kneaux if you change you mind... G

"Jim Weir" wrote in message
...
(COUGARNFW)
shared these priceless pearls of wisdom:

-Nobody looks it up. The 4522 lamp is usually used in a swing-down lamp.
The
-swing down lamp has a motor to drive the lamp up or down.

Yes, well, when you look it up, you might want to use the right number.
The
original poster said 4552, not 4522. If you had a clue about things, you
would
know that no 172 ever made had a swing-lamp setup. That died with the
C-170
series. Google on 4552 and see your error.



Well, Jim, I think you are being unfair to someone trying to be helpful, and
to be candid this guy Cougar from Sacramento has been very generous with his
expertise on the Stromberg carburetor and the files he has generated on it
and shared with some of us. If it weren't for these wonderful files (some
of which can be found at Ron Wanttaja's website), I wouldn't have been able
to make the neat little tool necessary to check and set the quirky float
level on a Stromberg. And yesterday after having spent a half day sweating
and changing out washers under the seat and checking and rechecking the
float level with gasoline in the bowl from a tube and a gallon of mogas
overhead, I thanked him every minute.

I was also grateful when the little C-85-powered taildragger's engine sprang
to life, purred, and flew gallantly aloft after I had finished doing a
bundle of wrenching and safety-wiring. And finally, thanks to Cougar
because it would have cost us over two weeks time and over $500 if we had
had to send that carburetor off for rebuild. And now we have a carb which
runs neither too rich nor too lean and doesn't leak gas all over the ramp.

So pick on someone who really deserves it, because he of all people, in his
kindness and generosity, should not be the butt of your caustic remarks.

You have been kind and generous with your technical advice. That is where
YOU shine, not at being mean.

Thanks Hank, lemme kneaux if you change you mind... G


You will be the first to know.
Hank

Nobody looks it up. The 4522 lamp is usually used in a swing-down lamp.

The landing lamp is a GE 4522.

If I posted different, then it is my error and I appologize.
Hank

If your lamp is a 4522 then it is a PAR46 bulb, 13 volts 250 watts
5.75 inch dia with a rated life of 25 hours. 250w/13v = 19.23 amps
not counting the initial surge of about 5 times the rated current. A
20 amp breaker is too small to power this lamp.
You can get lamps in this same size glass housing from 35 to 450
watts.

A 4552 lamp is a 250 watt 28 volt PAR64 lamp , 8 inch dia which is the
number you listed first This lamp will draw about 9 amps which is
about correct for a 20 amp breaker.

I suspect someone installed the wrong lamp in your aircraft. Many
14volt 172's use a par36, 4509 lamp which is rated at 13 volts, 100
watts, 7.7amps.

You need to look up in the parts list for the aircraft the correct
part number of the lamp.

On 21 Aug 2004 23:36:14 GMT, (Hankal) wrote:

Nobody looks it up. The 4522 lamp is usually used in a swing-down lamp.

The landing lamp is a GE 4522.

If I posted different, then it is my error and I appologize.
Hank

Jim Weir writes:


No, a loose ground AT THE LAMP will cause the wire and aluminum at the lamp to
get hot, but it won't pop the breaker. However, a loose or corroded connection
at the BREAKER will cause the breaker to heat up (I-squared R loss) and pop.
You might check the connections at the breaker before you go off on a tangent.


Best way: Turn on lamp; wait a minute. Wet finger, carefully touching
each breaker terminal w/ same wet finger. If you hear/feel sizzling,
withdraw....

If you don't, push a little harder until your fingertip IS in contact.
The screws should be equal temp; maybe warm but not hot.

(You CAN just use a dry fingertip; we'll know by the missing letters
in your next post.)


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

If he had simply stated that the bulb drew thus and such a current and was used
in a swing-down application, I would have simply stated that he was using the
wrong bulb number supplied by the original poster (who, it turns out, screwed up
and posted the wrong number to begin with).

Instead, he starts of with a particularly snotty "Nobody looks it up" when half
a dozen of us DID take the time to look up a rather obscure bulb and post our
findings.

He got a snotty answer back. End of story.

Jim



" jls"
shared these priceless pearls of wisdom:

-
-"Jim Weir" wrote in message
.. .
- (COUGARNFW)
- shared these priceless pearls of wisdom:
-
- -Nobody looks it up.

- Yes, well, when you look it up, you might want to use the right number.

-
-
-
-Well, Jim, I think you are being unfair to someone trying to be helpful


Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

I suspect someone installed the wrong lamp in your aircraft. Many
14volt 172's use a par36, 4509 lamp which is rated at 13 volts, 100
watts, 7.7amps.

You need to look up in the parts list for the aircraft the correct
part number of the lamp.

I did look at the parts manual and it states GE 4522 and the breaker is a 20
amp.
Would a 4509 or 4905 fit in the same housing?
Hank