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  #1  
Old 01-01-2022, 12:13 PM
osaleh osaleh is offline
 
Join Date: Sep 2010
Location: Houston Texas
Posts: 96
Default Hooking up multiple devices on same power pin

Hello fellow builders and a happy new year. Please excuse the question below, my electricity knowledge is lacking, thus i bought the VPX PPS and the VPX sport CB to make my life easier.

I am building RV7a. Situation is I have run out of all power pins on my VPX sport. I also discovered that i have to supply power to my ELT. it is the ACK E-04 406 MHZ ELT. It needs a 1 amp CB and little AMP draw. I also have one of the power pins (VPX 10A-4 output if you are interested) is dedicated for a USB outlet that draws 4AMPs. I set the CB for that to to 6AMPs. My question is can i piggy back my ELT power from this power pin? It would occur to me that if USB device is drawing 2 AMPs or 3 Amps when in use and the ELT is only drawing < 1 AMPs, will that not overload the 22 GA wire going to the ELT and the ELT itself? I was thinking about a resistor to add on the wire that is gong to ELT but not sure if that will cut the current for the whole circuit. I have a full dynon stack, just FYI.

regards
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  #2  
Old 01-01-2022, 02:48 PM
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Foghorn Foghorn is offline
 
Join Date: Feb 2018
Location: Virginia Beach
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Default

Page 23 para 4.13a has an option for additional pins.

https://verticalpower.com/media/atta...nual_rev-e.pdf

I have a VP-X and added an EBus to my system for everything I want to work if the VP-X decides to go south. That was my work around to free up VP-X pins.

Jeff
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  #3  
Old 01-01-2022, 04:00 PM
CoolDadTed CoolDadTed is offline
 
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The 22 gauge wire can handle up to 5A of current. Setting the breaker to 6A for that circuit opens you to the possibility of overloading that wire in the event that there is a fault in the ELT. The breaker must be configured to protect the wire.

Also, adding a resistor will drop the voltage to the ELT which will not be good.
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Last edited by CoolDadTed : 01-01-2022 at 04:26 PM.
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  #4  
Old 01-01-2022, 04:53 PM
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Isaac Isaac is online now
 
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Location: Peoria, Az
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Default RE: Hooking up multiple devices on same power pin

Instead of a resistor, how about using something like this inline fuse in series with the 22ga power wire to the ACK E-04 406 MHZ ELT. Use a 1 amp (or 0.5 amp) fuse to protect the wire.

https://www.digikey.com/en/products/...B-18B/11579217

Set the VPX to a value that support the current requirement of both devices on that output.
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  #5  
Old 01-01-2022, 05:42 PM
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RVbySDI RVbySDI is offline
 
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Get one of these.
https://www.steinair.com/?s=Fuse+blo...ct&dgwt_wcas=1

Power it off the main power feed to the VPX. Then wire the ELT or anything else you may need to it. They use standard blade fuses.
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  #6  
Old 01-14-2022, 06:00 PM
osaleh osaleh is offline
 
Join Date: Sep 2010
Location: Houston Texas
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Default Thank you All for the great suggestions

Thank you all for the great suggetions
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  #7  
Old 01-14-2022, 06:05 PM
osaleh osaleh is offline
 
Join Date: Sep 2010
Location: Houston Texas
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Quote:
Originally Posted by CoolDadTed View Post
The 22 gauge wire can handle up to 5A of current. Setting the breaker to 6A for that circuit opens you to the possibility of overloading that wire in the event that there is a fault in the ELT. The breaker must be configured to protect the wire.

Also, adding a resistor will drop the voltage to the ELT which will not be good.
Thank you Ted, if the ELT is only drawing 1AMP, will that still be an issue when using a 22 GA wire? so the ELT is 1 amp and is 22 ga and the USB draws 4 AMPs and i used 20 GA for that. They are both being fed from the same pin that is set to 6 AMP CB.
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  #8  
Old 01-14-2022, 10:35 PM
CoolDadTed CoolDadTed is offline
 
Join Date: Apr 2019
Location: Littleton, MA
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Quote:
Originally Posted by osaleh View Post
Thank you Ted, if the ELT is only drawing 1AMP, will that still be an issue when using a 22 GA wire? so the ELT is 1 amp and is 22 ga and the USB draws 4 AMPs and i used 20 GA for that. They are both being fed from the same pin that is set to 6 AMP CB.
Can you set the pin's threshold to 5A? That would protect both wires. Setting it to 6A is risking overcurrent on the 22GA wire. The ELT may normally draw 1A but if it fails, it might draw the whole 6A and overload the wire.

The circuit breaker should match the (smallest) wire it feeds.
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  #9  
Old 01-14-2022, 11:55 PM
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bruceh bruceh is offline
 
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I took one of the 15A circuits on the VP-X and connected it up to a small 8 fuse block (like Steinair's above). I run several other circuits like the ELT, interior lighting (LED's), and the Hobbs meter off of this. Set the circuit to be always on in the VP-X configurator. There is no need to have the VP-X switch on/off any of these circuits individually. The current draw on these is very minimal. I think if everything is on, it draws about 2 amps, so plenty of head room for expansion later if needed.
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  #10  
Old 01-15-2022, 06:56 AM
osaleh osaleh is offline
 
Join Date: Sep 2010
Location: Houston Texas
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Default Will do that

Quote:
Originally Posted by CoolDadTed View Post
Can you set the pin's threshold to 5A? That would protect both wires. Setting it to 6A is risking overcurrent on the 22GA wire. The ELT may normally draw 1A but if it fails, it might draw the whole 6A and overload the wire.

The circuit breaker should match the (smallest) wire it feeds.
I will set it to 5AMP CB. Thx
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