ION7650 Front Panel Display

[sesa74337_bridg]

Hi, All,

For the ION7650 meter front display, I always see the unit for the current is kA, not A, but in PME it shows Amps, just wondering if there is a way to force the front display show amps only?

Thanks,

James

[Charles_Murison · Accepted solution]

Summary

The front panel display on the 7500/7600/7550/7650 meters automatically scales to display voltage, current, and energy readings in appropriate units.  The displayed units cannot be changed because they are based on the CT / PT ratios.

The User Guide mentions these 'Automatic Units' but does not explain how to change the CT / PT ratios to obtain the desired units.

To change the way the 75/7600 scales voltage, current and power, adjust the PT or CT PRIMARY parameters as follows:

For V or A:              Make PT or CT Primary < 1000

For KV or KA:           Make PT or CT Primary within 1000 to 1,000,000

For MV or MA:          Make PT or CT Primary > 1,000,000

For kW:                    (CT*PT*3/1000) < 1000

                             (CT*PT) < 333,333

For MW:                  1000 < (CT*PT*3/1000) < 1,000,000,

                             333 < (CT*PT) < 333,333

For GW                   (CT*PT*3/1000) > 1,000,000

                             (CT*PT) > 333,333

NOTE: After scaling the PT PRIMARY, also scale the PT SECONDARY appropriately to maintain the same ratio.

Example:

If the actual PTs are 4160:120 and you want to display V instead of KV (i.e. 4260 V) set PT PRIMARY to 416 and PT Secondary to 12.

More Information

If these changes are made from the front panel, note that you will have to do each one separately.  During this time the meter will calculate 'wrong' values.

For example, using the case above, if you first changed the PT primary to 416, and then changed the secondary to 12, as soon as you make the first change (but before you make the second) the effective PT ratio becomes 416:120.  The calculated values in the meter for volts, power and energy will be 1/10th their actual values.  This is corrected as soon as you make the change to the secondary value.  This will affect the following functions (and maybe a couple others as well):

-Voltage and Power Minimums will likely drop to 1/10th their nominal levels

-Sag/Swell module will 'detect' a drop in voltage, trigger a waveform capture and create an event which will alarm in PEGASYS/ION Enterprise. This can be avoided by first disabling the sag/swell detection (either in Vista, or from the front panel by setting the Nominal Voltage to zero before making any other changes).

-Any Set points configured for voltage, current or power could be triggered.

If the changes were performed using ION Designer, all parameters can be changed simultaneously, avoiding the mentioned effects.

[sesa74337_bridg]

Thank you so much, Charles,

just in your example, you said "

Example:

If the actual PTs are 4160:120 and you want to display KV instead of V (i.e. 4.26 KV) set PT PRIMARY to 416 and PT Secondary to 12."

From I understanding, when the PT primary is set 4160, it should show kV already, right? Set to 416:12 should give you the unit in ' V', is that correct?

Thanks,

James

[Charles_Murison]

Correct, I have edited my orginal post to reduce any future confusion.

[solutions_iems-]

Hi

Can this way to change meter scaling be applied to other meters such as PM8000?

Thanks

[Charles_Murison · Accepted solution]

yes

[ingenierohector]

I use ION Setup the function on te option DISPLAYS - AMPS - EDIT - UNITS - A and ready: always display ampers in A in the Front Panel Display.