DC clamp meter

Estragon
Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
So I got my new clamp meter:
https://www.amazon.ca/gp/aw/d/B0166GK8Q2/ref=mp_s_a_1_1?ie=UTF8&qid=1527080621&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=ut203&dpPl=1&dpID=41LRqdsC1GL&ref=plSrch

The instructions are only in Chinese, so not especially helpful.  Maybe some out there has one and can help me in using it properly for measuring DC current.

It has 3 buttons; Select, Rel (delta symbol?), and Hold.  Select appears to toggle AC and DC when the dial is set to 40A or 400A for current measurement.  I assume the Rel button is used to zero it before clamping a conductor, and Hold is to keep the reading while unclamping?  It's mainly the zeroing process I'm not quite sure of.
Off-grid.  
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter

Comments

  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,036 ✭✭✭✭✭
    I believe the select button will toggle between AC and DC. 
     Hold the Zero button for a few seconds, you should see the screen zero out.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,036 ✭✭✭✭✭

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,036 ✭✭✭✭✭
    I am getting the zero function confused between this and my Klein Tools clamp meter. After reviewing the manual , it seems there isn't a zero out function. 

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Seems strange there is no zero button, both of mine have one, Ideal and UEI, but the readings differ anyway, the Ideal is my go to meter, it cost 5 times what the UEI did, the one touch zero makes it easier, but for what we're doing accuracies need to be ball park. In my opinion. 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    edited May 2018 #6
    The Delta Button is the zero button... With no current flowing/no wire in jaws, just push once and the meter should read 0.0

    It is also intended for measuring differences in current flow. Put on wire with current flowing and push delta button for zero. Then if the current flow goes up or down, then the meter displays the difference (i.e., zero at 10 amps. Then if current goes to 11 amps, meter will show 1.0 amps or the Delta/Difference in current flow).

    Note that DC meters do show +/- for direction of current flow (AC current meters do not).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Thanks guys, that helps. In playing around with it a bit, the zeroed meter reading seems to wander a bit, but should be close enough for most of my needs.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Yea, DC meters use a "Hall Effect" transistor to measure the magnetic field around the wire. They do drift some over time and temperature. For lower currents, you do need to re-zero the meter ever few minutes for accurate measurements.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset