Inrush currents of motors, power transformer, capacitor banks can be measured using Chauvin Arnoux CA8335 analyser.
In this article will be described measuring inrush current of motor. The same measuring principles fits to power transformer and capacitor bank.
How to connect currents leads read article “Analyser Chauvin Arnoux CA8335 – 1. Transient mode” (particles 1 and 2). How to select measuring scheme and measuring method read particles 3 and 4 of the same article “Analyser Chauvin Arnoux CA8335 – 1. Transient mode”.
1. Setting of “Inrush mode” .
Press button as shown in the picture:
Figure 1
Select “Inrush current” in windows “Wavecapture”:
Figure 2
Press button “Enter”.
At window „Capture schedule“ select parameters as shown in picture:
Figure 3
„Start treshold“ – is setting of current. Analyser will record this current after exceeding this setting. I‘m going to measure inrush current of 400 V motor. Nominal current Inom of motor is 15 A. Usually inrush currents of motors are at interval 4÷10xInom. So I set „Start threshold“ parameter to 40 A.
“Triggering filter” – measuring phases quantity. I’m going to measure three phases, therefore “Triggering filter”= 3A.
“Hysteresis” – accuracy of measurments
“Start” – starting date and time of monitoring
- To start “Inrush mode” press yellow button below icon “OK” as shown in picture:
Figure 4
- “Capture on standby” window appears after starting of “Inrush mode”:
Figure 5
Analyser is now in monitoring mode. Analyser will record current after exceeding current setting (40 A).
- When motor is starting, window „Capture in progress“ appears in analyser:
Figure 6
At his moment analyser is recording currents.
- When record fill whole memory of analyser, such information appears on analyser’s window:
Figure 7
Memory is full, record is stopped.
- Opening record. Press yellow button below icon “catalogue” as shown in the picture:
Figure 8
“Capture parameters” window appears:
Figure 9
Parameter “Duration” indicates the length of record (2,367 s).
Press yellow button below icon “RMS”:
Figure 10
Currents’ RMS curves will be opened.
L1 phase RMS curve:
Figure 11
Fixed L1 phase maximum RMS value is 53,13 A.
L2 phase RMS curve:
Figure 12
Fixed L2 phase maximum RMS value is 55,91 A.
L3 phase RMS curve:
Figure 13
Fixed L3 phase maximum RMS value is 63,52 A.
Press yellow button below icon “Peak” as shown in picture:
Figure 14
Currents Peak-to-peak sine curves will be opened.
- When you need to record another inrush current, you must first to delete existing record to clear memory of analyser CA8335 . After deleting existing record, you can record new inrush current.
Deleting record.
Press button “Settings”:
Figure 15
Select option “Erase memory”:
Figure 16
Press “Enter”.
In window “Erase memory” select “Inrush current capture” as shown in picture:
Figure 17
Press “Enter”.
Press yellow button below icon “Bin” as shown in picture:
Figure 18
Record is deleted. After deleting exsisting record you can record new recording.
That is all. In the next article we learn how to record the whole motor’s starting process by using monitoring mode.