AC power cord length restrictions
AC power cord length restrictions
(OP)
I am trying to provide ac power to a chassis unit that is located 800' away. In this unit, I have four linearly regulated DC power supplies. I am considering in using an AC power cord to supply power to my power supplies. What is the length restriction for using ac power cords in the outdoors? Do I need driver amplifiers for my application?






RE: AC power cord length restrictions
Mike
RE: AC power cord length restrictions
1) What is the total power, in Watts, or VA, that you are tryng to supply, 800' away?
3) What is the required voltage?
3) Have you thought about splitting the 4 units up, and suppling them with a 3-ph/4-wire circuit?
RE: AC power cord length restrictions
For a related topic, see thread 278-44947,
"3-Phase to Single-Phase Current Relationships"
RE: AC power cord length restrictions
I am working in the US. My application is to remotely turn on power supplies at a distance of 800'. The supplies are located near an AC outlet, however, it is cumbersome to have to plug and un-plug an ac power cord. The ac outlet is located on a pier and I am on a cliff that is located 800' away.
Shortstub:
Here are my answers:
1) 70 watts
2) 120 Vac at 800'
3) No, I have not--it seems involved. The supplies have to be co-located and housed in a weather-tight enclosure. My application is to remotely turn on the supplies. I would like to have a 'toggle switch' that is 800' away. I am trying to avoid making many trips to this enclosure and turn on the supplies.
RE: AC power cord length restrictions
First, the load must be determined, and the voltage drop for this load must be calculated for this distance at the load's voltage (in a professionally installed wiring method). If the voltage drop is excessive (and it almost certainly will be), you may need oversized conductors or the use of a higher voltage for the 800', and then transformation down to your load voltage.
RE: AC power cord length restrictions
RE: AC power cord length restrictions
Running an 800 ft cord, especially when part of it is on a pier, would be out of the question. It would be dangerous and there would probably be too much voltage drop.
RE: AC power cord length restrictions
RE: AC power cord length restrictions
Another way to achieve hard-wired control would be to use a control relay or contactor to switch the loads. That way only a very small control-power current would have to traverse the 800-foot wiring run and voltage drop would become much less of an issue.
I agree that radio or phone might be more convenient and possibly cheaper.
RE: AC power cord length restrictions
For additional reference on extention cord please check the enclose report from the U.S. Consumer Product Safety Commission (CPSC).
http://www.cpsc.gov/cpscpub/prerel/prhtml99/99069.html
RE: AC power cord length restrictions
Something like a 24VDC "ice cube" relay [P&B KRP?] with small DC power supply may do the job. Consider 2-pair 24AWG telecomm cable: One pair to switch the realy coil and one to send back a contact closure.