How do you calculate CT metering ratio?

How do you calculate CT metering ratio?

When analog ammeters are installed, we can easily determine the CT ratio by observing the meter full scale value and then divide that value by 5.

How do you find the meter multiplier?

A) Meter multiplier : Is written on the name plate of the meter Ex. : MULT X 10 If no multiplier is written, the multiplier is 1. You have to applied the multiplier on each reading of your meter: KWh (consumption) KW or KVA (demand).

What is multiplier in meter reading?

The meter multiplier times the change in beginning and ending meter readings is equal to the actual energy use. All the hours of the year other than those that are on-peak. The hours during the year when demand for electricity is particularly high for Midwest Energy.

What is the CT ratio?

Ratio. The CT ratio is the ratio of primary current input to secondary current output at full load. For example, a CT with a ratio of 300:5 is rated for 300 primary amps at full load and will produce 5 amps of secondary current when 300 amps flow through the primary.

How do you calculate the multiplying factor of a Wattmeter?

for finding the multiple factor of wattmeter Step3: The Multiplication Factor (MF) is: MF = (voltage range x current range x power factor)/(range of the wattmeter scale)…

What is the formula for calculating the multiplier M2 transformer?

Calculate the M2 money multiplier using the following formula: M2 = 1 + (C/D) + (T/D) + (MMF/D)/[rr + (ER/D) + (C/D)].

What is class1 CT?

The class designation is an approximate measure of the CT’s accuracy. The ratio (primary to secondary current) error of a Class 1 CT is 1% at rated current; the ratio error of a Class 0.5 CT is 0.5% or less. Errors in phase are also important, especially in power measuring circuits.

How do you calculate CT burden?

Burden for Metering type CT = Total Burden of Meters (Digital/Analog Ammeter, Voltmeter, Power Meter, MFM, Transducer) which are in series with CT + The total VA of the Cables connecting CT and the Meters. Cable VA = (2L x R x I^2).

When to use meter multiplier for CT and PT?

Meter multipliers are used when meters are installed in transformer-rated installations. If the CT ratio is 200:5, then the meter multiplier is 40, which is simply 200/5. If a service has both CT’s and PT’s then the two values are multiplied together to give the billing multiplier.

Which is the correct formula for circuit multiplier?

The amount by which the voltage and current are reduced is known as the circuit multiplier. Potential transformers (PT.Mult.) = 360 ÷ 120 = 3. Current transformers (CT. Mult) = 400 ÷ 5 = 80. Circuit multiplier = (PT.Mult.) x (CT.Mult.) – 3 x 80 = 240. The circuit multiplier (external) is not indicated on your meter.

What does 1000 mean in a CT ratio?

Here 1000 means it is a primary current and 1 means secondary current. Also, we can have rewritten as 1000/1. CT secondary current will be always 1 or 5 to get easy calculation as well as we can create small rating secondary circuits to withstand up to 5 Amps. Note: The sensitive metering CT always comes with the 1 Amps secondary current.

How to calculate the CT ratio of a transformer?

Let us take a simple example of a current transformer which is having CT ratio of 2000:1, assume that the CT primary has 1500Amps, calculate the secondary current with respect to the primary. The CT ratio is the inverse of the voltage ratio. If your transformer has a voltage ratio is 1:25 means, the CT ratio would be 25:1.