RPICT Buying Guide

We aim to answer here most commonly asked questions at buying time.

Which RPICT board should I get?

The choice of the RPICT will depend on the following factors.

• Number of channels.
• 3 phase or single phase.
• Is temperature needed.
• Is a voltage sensor needed.
• RaspberryPi standard or RaspberryPi zero.

Do I need a voltage sensor?

If you are looking to estimate power consumption or detect if a device is on or off then you probably do not need a voltage sensor. In this case we use what we call 'Estimated Power'. RMS current is measured and multiplied by a fixed estimated voltage (say 240, 200 or 110V) to get an estimated power value. You can alternatively just read the RMS current in Ampere if you prefer. RPICT boards used for this are commonly RPICT3T1 RPIZ_CT3T1 and RPICT8.

If you are looking to measure Active Power, power factor and the like then clearly a voltage sensor is needed. This is also the case if you need to know the direction of power (import/export). Using a voltage sensor can also be used to allow measuring smaller power devices. For this we would use RPICT3V1 RPIZ_CT3V1 RPICT7V1 RPICT4V3 RPIZ_CT4V3T2.

Which rating is best for me?

To make things easier we ask that you indicate in 'rating' option which CT you plan to use and the max range that you intend to read. All our board are manufactured for SCT-013-000 100A. This is why there is a small fee to convert them for another CT or range value.

First of all you should estimate the highest current value your system is likely to have. Then pick a rating just above that. If you do not know just use the 100A to start with