The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
Earthquake in New Zeeland
by RODALCO
11/27/16 11:25 PM
Calling all Non-US members!! (Non-US only)
by Tjia1981
11/27/16 06:33 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 9
Texas_Ranger 8
sparkyinak 7
Trumpy 6
Who's Online
1 registered (sparkyinak), 245 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#213864 - 08/18/14 10:24 PM KWH readings, line and load side of transformer
captzap Offline
New Member

Registered: 08/18/14
Posts: 4
Loc: FL.
would the KWH readings be the same on the line side of a 480 volt transformer and the 208 load side of the transformer minus the efficiency effects?

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#213867 - 08/19/14 06:47 AM Re: KWH readings, line and load side of transformer [Re: captzap]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
By math, yes.

Welcome to ECN
_________________________
John

Top
#213869 - 08/19/14 09:09 PM Re: KWH readings, line and load side of transformer [Re: captzap]
captzap Offline
New Member

Registered: 08/18/14
Posts: 4
Loc: FL.
Thank you.Installing Emon-Demon system for tenant metering

Top
#213870 - 08/19/14 10:53 PM Re: KWH readings, line and load side of transformer [Re: captzap]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
The difference should be a fairly accurate measurement of the various losses in the transformer and associated wiring.
Virtually all of the loss is eventually going to end up as heat, as is the case in anything electrical.
When we were calculating HVAC loads in computer rooms the sensible heat always included the total electrical input to the room at 100%. (3412.142 BTU per KWH, usually rounded off to 3400)
_________________________
Greg Fretwell

Top
#213871 - 08/20/14 06:23 AM Re: KWH readings, line and load side of transformer [Re: captzap]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Just an FYI, follow the Emon install instructions...
_________________________
John

Top
#213874 - 08/20/14 09:20 PM Re: KWH readings, line and load side of transformer [Re: captzap]
captzap Offline
New Member

Registered: 08/18/14
Posts: 4
Loc: FL.
Yes, it was designed by an engineer who shows 2 sets of ct,s on the load side of transformers. This will work in favor of the tenant. I would correct this but they sent 208v meters, need 480v meters to make it work. The landlord will have to take the heat.

Top
#213875 - 08/20/14 10:35 PM Re: KWH readings, line and load side of transformer [Re: captzap]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
If the tenant is actually supposed to pay for what they use, the CTs should be on the load side of the transformer.
The transformer is the landlord's equipment and he needs to recover that money somewhere else in the rent, just like he has to do with parking lot lights and exit signs.
_________________________
Greg Fretwell

Top
#213877 - 08/21/14 09:38 PM Re: KWH readings, line and load side of transformer [Re: captzap]
captzap Offline
New Member

Registered: 08/18/14
Posts: 4
Loc: FL.
Thanks for the input, system is up and running. Now it is time to teach the landlord how to read and bill for KWH & demand

Top
#213878 - 08/21/14 10:43 PM Re: KWH readings, line and load side of transformer [Re: captzap]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
I assume this is sub metering (landlord owned meters). He will need to compare the total PoCo bill to what he records for each tenant and consider the difference "house load" and recover that in another manner.
I am not sure where you are but in Florida they have to bill sub metered power at the same rate they pay, including all attached fees. They can't tack on a landlord service fee or increased rate as part of the power bill.
Prior to that law, there was lots of abuse. Places like trailer parks were marking up the power 100%.
_________________________
Greg Fretwell

Top
#213880 - 08/22/14 08:11 AM Re: KWH readings, line and load side of transformer [Re: captzap]
ghost307 Offline
Member

Registered: 05/09/05
Posts: 884
Loc: Chicago Illinois USA
Be sure that he doesn't make a profit on the resale of electricity. Even if it's an honest mistake you risk being on the wrong side of the law.
Their best bet would be to contact the local Utility to make sure that they're allocating the electric costs properly and within the rules.
Here in ComEd territory...resale isn't allowed no matter how you split up the bill (which is overkill IMHO).
_________________________
Ghost307

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals