Varlogic NR6 -N12

[hasanhadi]

hi
how setting Varlogic NR6 -N12 if cabacitor bank has two stage has same power 500kvar ,6600v ,ct=3000/5
voltage in device 110v by using vt 6600/110
can be setting Varlogic NR6 -N12 to reading true power i mean source voltage 6600 but voltage in device 110v how matching between this voltage to obtain true reading in medium voltage

 

[hasanhadi]

please i need answer for this equation
the answer very important

 

[DTR2011]

sounds like a VT (Voltage Transformer) is involved from the 6.6kV to the controller. IN some parts of the world it is the week end and considering this is a forum, advise is free.

 

[DTR2011]

Here in the US we have a saying "RTFM" read eleswhere for translation.

You need a VT connected to the 6.6kV (6600:110). Follow the instructions on pg 27 of the manual CAREFULLY.

It appears that the scaling will be in secondary values only. I would recommend some kind of spreadsheet be made to calculate equivalent HV values. Print out the spreadsheet and keep near the meter for future reference.

From the Manual:

6.3 High Voltage use of NR6/NR12
This controller is primarily intended for LV network, but may be used in HV networks under
the commissioner’s full responsibility, if the following points are taken into account.
Connections must employ VT and CT with respect to the following figure.
In HV applications the power values displayed in Measurement Menu represent only the secondary
side values of the VT. To avoid potential misunderstandings, set the CT ratio to percentage
scale.
Safety (or reconnection) delay must be adapted to the value of the discharge resistors of the
capacitors, the most usual value is 10 minutes (600 seconds). The controller’s default response
delay is adapted for LV use. Using too short a response delay may damage the capacitors.
Important:
• the whole commissioning process must be performed using the Manual setup menu and
Parameter menu
• the commissioner should not use Bank Pre-Configuration and Commissioning menus

 

[hasanhadi]

Mr.smallgreek
what is mean set the CT ratio to percentage scale?

 

[hasanhadi]

what is mean set the CT ratio to percentage scale?

 

[hasanhadi]

what is mean set the CT ratio to percentage scale?
also when change to the ct ratio to percentage scale on effect to power factor
i need example please how matching if I=400A and vt=110 volt,pf=0.9
but voltage source 6600V
now power=1.73x110x400=76.2kw
but true value=4.57MW

 

[burnt2x]

Clear your mind. Use values properly.

If you compute using secondary values, you use the multipliers (CTR x VTR). I guess 400A is a primary value and 110 is a secondary value. Else:
P = 1.732 x 6,600 x 400 = 4.57MW

 

[hasanhadi]

i know but Varlogic NR6 -N12 cannot reading true power i mean source voltage 6600 but voltage in device 110v how matching between this voltage to obtain true reading in medium voltage
in maunal said
In HV applications the power values displayed in Measurement Menu represent only the secondary
side values of the VT. To avoid potential misunderstandings, set the CT ratio to percentage scale
.now how using CT ratio to percentage scale
and found effect to power factor

 

[burnt2x]

Please go back to the user manual and try the "AUTOSET" menu. You just need to input 3 parameters; CT, VOLTAGE and COS PHI and let the unit search for the others. It's there, it just need more reading. Better still, have Schneider rep to help you. Hope that helps.