TRIPLETTLoop CoilInstruction ManualPN 84-730 Rev BTriplett Corporation One Triplett Drive Bluffton, OH 45817800-TRIPLETT FAX: 419-358-7956
substation and sent to the customer site. In either case, the harmonic current flow along the power linelooks the same (as far as the Loop Coil is co
reverse the polarity of the magnetic field radiating from the line following the transformer. This does notcause any cancellation of magnetic fields,
Harmonic currents can also come from a lightly loaded transformer. Transformers “reflect” their sec-ondary load current into their primary winding.
9.4: TRANSFORMERSThere are several types of transformers that are often seen on the power lines that parallel telephonelines. The transformers at the
What does this mean to us? It means that loads like industrial motors often don’t represent a very goodpath for harmonic currents to flow through, i.
unless there is some source of harmonic current. For our example, we’ll accept that the transformer is“over-excited” (has too much voltage applied to
In the MITIGATOR Applications Manual, we noted that in order for noise to appear on a phone line, therehad to be Influence, Exposure, and Susceptibili
11.1.1: Over-Excited TransformerWhen a transformer is over-excited by excessive primary voltage, it can create a harmonic current flowif there is suff
12 Pulse: 660Hz, 780Hz, 1380Hz, 1500Hz, 2100Hz, 2220Hz, 2820Hz[550Hz, 650Hz, 1150Hz, 1250Hz, 1750Hz, 1850Hz, 2350Hz]11.1.6: “Off Frequency” Harmonics:
suggest that there aren’t pieces of test equipment that the power company can use to measure har-monic currents. There are. Two of the more common b
Triplett Loop CoilInstruction ManualNOTE:This manual covers both the 60Hz and 50Hz versions of the Mitigator. The parameters shown in [ ] arefor the
If capacitor banks are creating a resonant condition at a harmonic frequency, it may be possible to movethe capacitor bank to a different location, th
The capacitors’ connection to the neutral and the earth ground are the culprits in this game. As alreadyexplained, capacitors act as very good harmon
Unfortunately, the earth ground also creates a path for the Ground Return Currents to flow through.What if current flow could be confined to the neutr
single bushing capacitors will not have a “live” housing (except under power fault or surge conditions),it is still recommended that the capacitor ban
Note: SNC is a manufacturer of HSRs and is very knowledgeable about their use. They offer a “whitepaper” and a video tape that describes HSR applicat
If the harmonic currents could be confined to the area where there is no exposure, then no noise wouldbe induced into the phone line. So how do we tr
SECTION 6: POSITIONING THE LOOP COILThe purpose of the Loop Coil is to measure the strength of magnetic fields emanating from power lines inthe vicin
Perhaps the easiest mounting is simply to fabricate a few “S” hooks from coat hanger wire and to hangthe coil on one of the car windows. The coil can
Figure 4Another example of a “Homemade” Mounting Bracket6.1: DON’T BE FOOLED!The Loop Coil only responds to magnetic fields whose lines of force pass
Figure 5When the Lines of Magnetic Force pass throughthe opening in the Loop Coil, the Loop Coil produces an output signal.Figure 6When the Lines of M
SECTION 7: CHOOSING THE RIGHT FILTERThe signal output (voltage) of the Loop Coil increases in strength as the frequency of the magnetic fieldincreases
Some noise mitigating craftspersons may opt to use the CMSG (C-MESSAGE) [PMSG] (PSOPHOMETER)filter instead of either the 20/F [1/F] or FLAT [NONE] fil
rectifiers. In general, in order for enough current to flow to create a detrimental magnetic field, thecustomer is usually a relatively large power u
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