Question 1

I would like to read wattage on a 240vac circuit, which in usa is two 120vac legs that are 180 degrees out of phase.  Is there any easy way with 1 CT

Accepted Answer

This may help you:  In order to PROPERLY read current on split phase systems like a typical house, You need THREE Current transformers and meters (NOT 3-PHASE!).
1 on L1, 1 on L2, and 1 on NEUTRAL (ALL of them)  The neutral leg will show all 120v current on BOTH busses.  The other two will allow you to separate viewed currents of the 240 from the 120 devices:

IE: meters show:  L1 - 10A  L2 - 12A , Neutral - 2 A.  THAT would mean your 240v devices are pulling 10 A and The devices on L2 to neutral (120v) is pulling 2A.  Another example:  L1 - 12A, L2 - 13A  Neutral - 5A  Tis would be: all 240 devices pulling 10A   120v Bus L1 is pulling 2A, and 120v Bus L2 is pulling 3A.  FInal Example:  L1-13A, L2-12A, Neutral - 25A.  This would show NO 240 devices drawing power, 120v L1 Bus draws 13A , 120v L2 Bus draws 12A.  This may be a little confusing at first, but work it out in your head, you will see.

Question 2

Can this meter run for long periods of time when connected to a 7000 watt generator?

Accepted Answer

I have a dozen of these in various electrical loads in my plant, they run 24x7 and are over 1 year old, no problems.

Question 3

Does this include wiring requirments. the q and a make it seem as this is just the lcd for an remote unit.

Accepted Answer

There is a simple picture on the box. Two wires for volts, for 120 on to power, one to neuteral. For 240 both to power. The inductor has to have a power wire run through the center. I had to extend the leads on the inductor on all 5 i have used. I hope this  helps.

Question 4

I want to measure the power of a pool heat pump using 240 ac in us measurements. do i take both legs (using 2 meters) and combine the readings?

Accepted Answer

If you don't mind doing the math you can use 1 meter and measure 1 side of the 240v (120v) . Example: If it draws 35 amps on the leg (phase) your reading it will draw 35 amps on the other. Same formula, if it shows 4.2 KW on the leg (phase) your reading then it will draw 4.2KW on the other. This would make the total KW of the heater 8.4 KW or 8400 watts. This meter will show you volts, amps and KW

ASIN	B014W3D1OC
Brand Name	DROK
Color	Black
Customer Reviews	4.2 4.2 out of 5 stars (352)
Included Components	No
Item Dimensions	9 x 5 x 2.5 centimeters
Item Weight	40 Grams
Manufacturer	DROK
Maximum Operating Voltage	260 Volts
Measurement Type	Ammeter, Multimeter, Voltmeter
Minimum Operating Voltage	80 Volts
Model	200123
Power Source	Solar
Style Name	Digital
UPC	682516775469

DROK AC Voltage Current Monitor, AC 80-260V 100A LCD Display Digital Volt Amp Power Watt Energy Multimeter Ammeter Voltmeter

Details

Details

Description

Specifications

Reviews

Common Questions