Maximum current surge calculation for hook up wire

[hinged]

Good Morning.
I am interested in calculating what the maximum current surge and duration could be in a 22 gauge conductor. The conductor is a 22 ga,strand 168/44, soft bare copper, insulated with a soft flexible PVC insulator. Operating temp is -40^C to +80^C. Max. voltage 600., nom. OD .054", nom. wall .010".
Maximum current carrying capacity is 4.6 amps per conductor.
There will be 4 conductors, approximately 24" long.
Power supply could be regulated 24 VDC @ 2 amps, or 24VDC @ 1 amp or 12VDC @ 2 amp.
I'm not sure if this is all of the required information, any help would be greatly appreciated, I'm not an EE or ME so laymans terms would be great.
Thanks

 

[jims99]

The wire you’re describing has capability of carrying about 8 amps continuously, at 80C. (Ref: Alpha Wire chart:

http://www.alphawire.com/PAGES/383.CFM

)

However, generally you would not want to push it to its specified limits (will cause wire to heat up). A good and conservative rule of thumb is that you run it at half its rating, around 4 amps. If your application is for 4.6 amps I would use 18 ga.

Your info is a bit confusing. I thought you implied that in YOUR application, you will carry 4.6 amps thru the wire, but then you mention a power supply limited to 2 amps - ???.
We need little more clarification.

jim s.

 

[hinged]

Jim S.
Thank you for the reply.
WHat the wire is used for is to carry current thru a hinge to power door devices.
These will all vary in requirements, none that would exceed the capacity of the wire, except in one situation because of the inrush current.
What we have is a latch device, solenoid activated, that has 24VDC continuous duty, with a current inrush of 16 amps for 300 milliseconds.
They state that a power supply that has a regulated output of 24VDC @ 2 amp.,standard input is 120VAC @ 1.0 amp or 240VAC @ 1.0 amps.
I understand that our 22 ga will not handle this inrush.
The wire according to the mfg is commercially rated at 4.6 amps.
Because of physical size we cannot use larger gage wire.
What i'm searching for is to find what the maximum inrush current the existing 22 ga wire is capable of handling and for what lenght of time.
Cold it handle a 10 amp surge for 300 milliseconds without damaging the wire?
I hope this clarifies the question>
Phil

 

[jghrist]

Should be the same as the short-circuit capacity. See

http://www.airpaxppp.com/pppsite/copscir.html

 

[RAMConsult]

Correct me if I'm wrong but I believe you want to know if the wire will fuse (burn-out) during the short time that door opening solenoid draws its charging current which is four times the wire's maximum current.

It should not be a problem. As the attached chart shows you can safely carry 30 amps for at least 3 seconds on a piece of bare #26 wire (I decreased the wire size to account for the heat retention effect of the insulation.)

http://mgc314.home.comcast.net/fusing.htm

Your bigger problem is the annealing of the wire from this heating effect combined with the constant flexing (work hardening) of the conductor. Testing is the best way to reveal the number of open-close cycles your wire will tolerate.

 

[advidana]

Check with the people at UL to see if it is acceptable.

 

[jims99]

Hinged,
The other posts are all correct. What you need to concern yourself with in this application is electrical SAFETY. In the event of a single fault condition, such as the solenoid being “stuck” on continuously, the wire will be subjected to continuous 10 amps, that may cause insulation to burn away (fire?). I would suggest that you follow regulatory agency approval codes (such as advidana’s advice for UL) and look into adding a protective device such as a circuit breaker or a slow-blow fuse.

jim s.

 

[hinged]

Good Morning,
Thank you everyone for responding to my thread.
It was very helpful.
Have a great day.
Hinged