Very simple to control any charger current by using your fingers and a set of display meters.
I am using a PFC charger that has a maximum AC input of 50 amps. You do not use a standard thermal circuit breaker for 50 amps, but 125% over the actual AC input which would be 62.5 amps. I use a magnetic trip breaker for 60 amps. Before I turn on the charger, I turn on the AC input power to a contactor Line terminals only. This AC contactor is between the main input 50 amp 4 wire plug and charger and a onboard chassis mounted 60 amp ground fault circuit break and than to the onboard charger. The AC display panel comes on, showing 250 volts AC and 0 amperes AC and a 250 volts DC and DC amp meter. Next, I turn on the battery box explosive proof exhaust fan to purge any battery vapors they may be. This fan must first come on first, because it has a interlock control circuit to turn on the AC input contactor. I then make sure that the current control of the charger is turn all the way down to 0 amps before I turn on the charger. Turning on the charger, I then raise the current watching the AC and DC amperes. It does not matter what AC voltage I am using, it can be any voltage from 90 to 250 VAC. To know what the maximum current should be, this depends on the current rating of the device you are plugging into. For example if you are connecting to a standard 20 amp 125 volt 3-wire receptacle, then the maximum current you should draw from that receptacle is 80% or 16 amps. On a 15 amp 125 volt 3-wire receptacle it should be 12 amperes. The maximum length feeder wire between the receptacle and circuit breaker panel on a 15 amp rated receptacle is about 50 feet for a No 12 Awg copper wire. Over 50 feet, use a No. 10 AWG copper wire for the first 50 feet, and then you can drop down to a No. 12 AWG for the next 50 feet. If you use a heavy duty industrial grade receptacle on a magnetic circuit breaker, than you can go up to 18 amps for a No. 12 AWG copper wire on a 20 amp breaker on a feeder wire not more than 20 feet to the circuit breaker panel. Roland ----- Original Message ----- From: "tomw" <[email protected]> To: <[email protected]> Sent: Thursday, May 23, 2013 7:50 AM Subject: Re: [EVDL] EVLN: Think Before You Plug In > "/But to install an affordable off-the-shelf 10K on-board charger, the > charger had better have the ability to draw only what is being supplied. > i.e.: plugging a 10K on-board charger into a typical 6kW public EVSE > will pop the breaker feeding 6kW EVSE (or the EVSE will shutdown/be > damaged). Meaning the on-board charger had better have some smarts to know > to turn itself down according to the capability of the source/." > > It does have communication capability for J1772, but of course can't > communicate with a wall socket. For that the driver has to have some > smarts. When the charger is started up the software gives the opportunity > to input the charging power you want. If plugged into a 120V socket the > software automatically limits the power. Yes it is the EMW charger Corbin > referenced. > > Sure it cost more for higher current level 2, but I would guess it is > still > considerably less costly than installing a DC fast charger. I would think > you only need the latter for longer trips along routes between cities, > somewhat like Tesla is locating their superchargers. > > > > > -- > View this message in context: > http://electric-vehicle-discussion-list.413529.n4.nabble.com/EVLN-Think-Before-You-Plug-In-tp4663123p4663159.html > Sent from the Electric Vehicle Discussion List mailing list archive at > Nabble.com. > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
