Energy Measurement

Please rephrase the question, as its meaning is unclear.

I pick C

The energy meters are probably bidirectional, and are reading the same either way...check the model #'s and contact the supplier for spec info....You might have the wrong meters for your application....

http://www.powerlogic.com/product.cfm/c_id/1/sc_id/6/p_id/23

I choose "E" None of the above.

I know there is a question in there somewhere?

Can someone translate please?

42

for metering purpose polarity of CTs are not a matter, it will measure the disregard the direction of current, so when the bus tie is closed the bus energy meter will read the power of bus which the transformer is not connected, i hope there is only one bus tie, what do u mean by all tie feeders?

"...polarity of CTs are not a matter...", absolutely wrong, the direction of the current through a CT determines its phase relationship with the voltage and whether the power is flowing into or out of a circuit. Incorrect wiring is a common problem, along with improper ratio/meter constants, for energy metering and billing problems/disputes.

You're running hot here mate. Didn't give you a GA for this one even though it's right on the money. A little of topic but not worth an OT rating. _{Already gave you a GA for your last comment which covered it.}

Wish OP all the best.

dear sir,

i mean in this system v r talking abt bus tie ct only, it has to measure the bus current only when, ie when bus tie is on, only one incomer will be in closed condition so it will measure the power of the bus which the incomer is not connected

Energy meters have no directions meaning its only voltage and currents which are -ve and on top of that energy has no -ve sign.So it will read in both the directions..

You cannot make those statements without knowledge of the meter. Depending upon the requirements of the local utility company some energy meters have a ratcheting mechanism that will only allow the meter to record energy flowing to the customer, not from the customer to the utility.

Energy does indeed have direction, it flows from the source to the consumer. If it didn't have direction how else would you get credit when your solar system was producing excess energy and putting it into the network? Meter polarity is very important and must not be ignored if you are to expect proper billing.

Energy is not a vector is what I think is meant but just because it's not a vector doesn't mean it can't be added and subtracted.Getting the meter sensor polaritites around the same way will make sure that the energy's exit or ingress is correctly reported on a mter.

I think you are right about the meters only recording energy that's sold and not creditting donor sources. The whole grid connect issue again. Utilities don't really want your energy.

Correct, energy is the dot product (scalar multiplication) of two vectors and results in a scalar quantity; however, scalar quantities have a sign (+ or -) associated with them, otherwise why would we need the absolute value function.

Then there's the story of the ATS connected on the wrong side of the meter.

Burning diesel and spinning the billing consumption meter.

Still better than the one that lit up the whole street........