wiring 4 battery chargers for forlifts

Status
Not open for further replies.

tim89s

Member
Location
Brush Prairie WA
I am assuming these chargers will run for more than 3 hours. I would like to run one circuit to
the chargers than tap to each charger. Do I need to add the nameplate plus 125% for each
charger or do take 125% of the largest one and add to the other chargers nameplate?
Thank you
Tim
 
Do the manufacturer's instructions tell you things like MCA/MOP or whether each charger must be on it's own circuit? (I haven't looked at a large charger in years.) You may be better off to run a feeder to a subpanel co-located with the chargers instead of tapping. Still need to do the feeder calc, though.
 

tim89s

Member
Location
Brush Prairie WA
Great idea of setting a sub panel. Its a lot cheaper. The nameplate for the chargers is 19, 19, 18, and 13 amps. The chargers are all 3 phase 480 volt. When doing the feeder calc do I take 125% of the largest one, or 125% of all, or do I just take the nameplate?
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Great idea of setting a sub panel. Its a lot cheaper. The nameplate for the chargers is 19, 19, 18, and 13 amps. The chargers are all 3 phase 480 volt. When doing the feeder calc do I take 125% of the largest one, or 125% of all, or do I just take the nameplate?

You might see if there is a charging curve in the installation manual. I seem to recall that chargers nowadays don't pump out at their rated capacity for the entire charge cycle. You may pull 19 amps for the first 15 minutes, 18 for the next 20 minutes, etc. Maybe the multiplier should only be for that amperage at the 3 hour mark? :?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
You might see if there is a charging curve in the installation manual. I seem to recall that chargers nowadays don't pump out at their rated capacity for the entire charge cycle. You may pull 19 amps for the first 15 minutes, 18 for the next 20 minutes, etc. Maybe the multiplier should only be for that amperage at the 3 hour mark? :?

I agree with you that the load is not really continuous, but I am not sure that a steadily decreasing load is non-continuous as defined by the code.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
NEC:
Continuous Load. A load where the maximum current is
expected to continue for 3 hours or more.

IMO, based on chargers I have seen, you don't have a continuous load but as gadfly suggests, check with the manufacturer for current curves.
As far as the feeder is concerned, I think it would be extremely unusual for it to see full load of all chargers for 3 hours or more.
That said, few locations that would have four fork lift chargers desire "minimum standards" anyway..
 
Last edited:

jusme123

Senior Member
Location
NY
Occupation
JW
You might see if there is a charging curve in the installation manual. I seem to recall that chargers nowadays don't pump out at their rated capacity for the entire charge cycle. You may pull 19 amps for the first 15 minutes, 18 for the next 20 minutes, etc. Maybe the multiplier should only be for that amperage at the 3 hour mark? :?


:happyno:...and what if all the chargers where plugged in at the same time?
 
Status
Not open for further replies.
Top