What do you think about this?

[killivolt]

I have an AMX Touch Panel rated at 12vdc, 3amps.

I contacted the Company and their engineers with a Question? could run the panel away from my switcher to another location 104' feet away.

The Voltage drop on 14guage wire would be 8vdc.

So, I asked for a power supply to directly power it and safeguard the Panel.

But, the power supply they sent me was 12vdc @ 2.8amps.

The panel ran all day just fine, then stopped working at the end of the day. I reconnected the Panel in the previous location luckily it still works in that location.

Is their unseen damage to the Panel and if so, should I take this up with them and their engineers?

They could have easily sent the 4.4amp power supply instead this one 2.8amps.

What do you think?

 

[Reloadron]

A few things I don't understand here. AWG 14 wire has a resistance of 2.525 Ohms per 1,000 foot. Therefore a 100 foot run of AWG 14 would have a resistance of about .2525Ω or round trip about .505Ω. Even with a 3 amp load out there the voltage drop on 100 feet of AWG 14 should be about 1.515 volts. Therefore 12 - 1.515 = 10.485 volts at the load so where does this 8 volts come from? I am missing something here.

However, a device rated at 12 Volts 3 amps would likely have problems running on 10.485 (10.5) volts.

Ideally you want a supply with an adjustable regulated voltage out so you could increase the output voltage to about 13.6 volts and capable of at least 3.5 amps. I didn't look at the resistivity of AWG 12.

They could have easily sent the 4.4amp power supply instead this one 2.8amps.

Regardless of the current rating of the supply you will still have the I * R loss in your supply lines. That is how I see it anyway.

Ron

 

[BrownOut]

so are you saying the panel was running all day on 4V? Did the 2.8 A power supply survive the day? If the panel is working now,it's probably OK, and there was another reason it stopped working.

 

[killivolt]

Thanks reloaddron for your reply.

The Voltage Drop was not my Calculation. I was about to buy the 14gauge wire suggested by the Company, I suddenly had doubts and asked an Electrician what the Voltage Drop would be. He looked it up in a book and came back with the 8vdc drop and I accepted it.

I am running Cat5 for the RS232 estimated at 104'feet. I put their suggested power supply in that location with the panel to avoid Damage.

But, it went into shutdown after I put it to sleep at the end of the day then powered it back up and I had lost com all together. In a panic I returned it to the previous location 15 feet away from the equipment and it was ok, for now? The only thing different is it is closer to the original power supply which is rated at 4.4amps. I would remove that power supply to run the panel but the switcher is sharing it with the panel.

 

[killivolt]

I didn't even think to look at the power supply.

Thanks

 

[killivolt]

I'm going to get the other power supply and do it again to see if it is the power to the Panel.

If it doesn't work then I will assume the Com lines are to long.

 

[killivolt]

However, a device rated at 12 Volts 3 amps would likely have problems running on 10.485 (10.5) volts.

Ideally you want a supply with an adjustable regulated voltage out so you could increase the output voltage to about 13.6 volts and capable of at least 3.5 amps. I didn't look at the resistivity of AWG 12. Ron

This is what bites my butt on this, they sent an under rated power supply when they had a power supply capable of delivering enough power ? WTF

 

[Reloadron]

Something else you mentioned:

But, it went into shutdown after I put it to sleep at the end of the day then powered it back up and I had lost com all together.

I can't help but wonder if this is a sleep related issue more than a problem with the cable length. Standard CAT 5 I think you are good for about 300 feet. However, back to the system waking from sleep. Some systems don't wake well from a sleep mode. Also some systems like to drop communications when in sleep mode. Maybe just for the heck of it look over your sleep settings.

Ron

 

[killivolt]

Good idea's.

Thanks you guy's. I know I can depend on you here for info like this, it's good to be back.

kv

 

[Reloadron]

Good idea's.

Thanks you guy's. I know I can depend on you here for info like this, it's good to be back.

kv

Yeah, was nice to see you visiting and hanging out here again.

Ron