ReDirect
Member
A lurker surfaces....
First off I would like to say thanks for all the good info from everyone who contributes on RIU!
1 - Power Factor
I built an LED grow light and am trying to calculate some efficiency numbers.
I add up the output of the 3 - MW HLG-240H-C power supplies (using a Fluke 79)
114v 2.077a = 236.77w
1115v 2.097a = 241.15w
115v 2.1a = 241.5w
719.42w total
Powering them with 230VAC service at this load they should be 93.5% efficient
So, 719.42w/.935=769.43w.
My reading at the wall using a $20 ebay meter (not true RMS) shows 811W (not VA)
I was told that I need to adjust the Watts at wall using the PSs power factor
and that a true RMS meter would reflect this.
Meanwell's datasheet lists PF>=0.95/230VAC @full load.
Multiply the 811w by the PF .95 = 770.45w
This is pretty close to the 769w calculation based on PS efficiency.
So it looks correct and I want it to be correct... But...
I research it online and there is lots of stuff about power triangles and other fun stuff like
industrial customers get penalized if their PF is too low and residential customers don't get charged
but I am unclear as to whether or not I am using the unaccounted for 41w...
I would like to hear from some others that this is correct that the light is using 766w not 811w.
Just seems a little odd...
2 - Inrush Current.
MW HLG-240H-C datasheet says:
INRUSH CURRENT(Typ.) COLD START 75A(t =700us measured at 50% I ) at 230VAC
and
MAX. No. of PSUs on 16A CIRCUIT BREAKER - 3 units (circuit breaker of type C) at 230VAC
Since I have these on a 30A 230V breaker, I can hook up 6 units+-
6 x 75A = 450A inrush.... sounds like a lot.... but that is only 2 lights at 3ps per light...
So I installed a 30A double pole master switch between the breaker and the outlets.
Since 5 lights x 3ps = 15ps each drawing 3A =45A -(once they are on),
the 30A 230v breaker should have no problem.
So I flip the switch starting all 15ps at once (1125A inrush), no problem...
Done it dozens of times...
Anything I need to be concerned about?
First off I would like to say thanks for all the good info from everyone who contributes on RIU!
1 - Power Factor
I built an LED grow light and am trying to calculate some efficiency numbers.
I add up the output of the 3 - MW HLG-240H-C power supplies (using a Fluke 79)
114v 2.077a = 236.77w
1115v 2.097a = 241.15w
115v 2.1a = 241.5w
719.42w total
Powering them with 230VAC service at this load they should be 93.5% efficient
So, 719.42w/.935=769.43w.
My reading at the wall using a $20 ebay meter (not true RMS) shows 811W (not VA)
I was told that I need to adjust the Watts at wall using the PSs power factor
and that a true RMS meter would reflect this.
Meanwell's datasheet lists PF>=0.95/230VAC @full load.
Multiply the 811w by the PF .95 = 770.45w
This is pretty close to the 769w calculation based on PS efficiency.
So it looks correct and I want it to be correct... But...
I research it online and there is lots of stuff about power triangles and other fun stuff like
industrial customers get penalized if their PF is too low and residential customers don't get charged
but I am unclear as to whether or not I am using the unaccounted for 41w...
I would like to hear from some others that this is correct that the light is using 766w not 811w.
Just seems a little odd...
2 - Inrush Current.
MW HLG-240H-C datasheet says:
INRUSH CURRENT(Typ.) COLD START 75A(t =700us measured at 50% I ) at 230VAC
and
MAX. No. of PSUs on 16A CIRCUIT BREAKER - 3 units (circuit breaker of type C) at 230VAC
Since I have these on a 30A 230V breaker, I can hook up 6 units+-
6 x 75A = 450A inrush.... sounds like a lot.... but that is only 2 lights at 3ps per light...
So I installed a 30A double pole master switch between the breaker and the outlets.
Since 5 lights x 3ps = 15ps each drawing 3A =45A -(once they are on),
the 30A 230v breaker should have no problem.
So I flip the switch starting all 15ps at once (1125A inrush), no problem...
Done it dozens of times...
Anything I need to be concerned about?
