When the push button is depressed, DC current from a small
dry cell flows through the transformer winding. The momentary
induced voltage in the other winding causes the center-zero
millimeter to deflect in one direction. When the push button
is released, the reverse induced voltage causes an opposite
deflection.
The leads with the polarity marks are attached to the transformer
terminals having polarity marks. If the latter are correct,
the meter will deflect to the right when the button is depressed,
to the left when it is released. Incorrect polarity will
cause the meter deflections to be the reverse of the above.
The polarity checker can be used on all types of transformers
through a great range of sizes. It will operate equally
well on small electronic and instrument transformers, metering
transformers, both potential and current, and large power
transformers. A sensitivity control adjusts the current
to suit the size of the transformer to be checked.
In addition to checking the polarity of a single transformer
by itself, this device can be used to check out the correctness
of the wiring in a transformer rated meter installation.
To use the polarity checker for this purpose, connect the
test current leads to the isolated primary of one of the
instrument transformers, either potential or current. The
indicating meter leads are then connected to various terminals
on the test switch or meter.
The small panel meter requires no calibration, and the
size D dry cell is easily and quickly replaced.
SPECIFICATIONS
Power: one D size dry cell
Size: 3 3/4” x 6 1/4” x 2 3/4” (9.5 cm.
X 15.9 cm x 7 cm
Weight: 1 lb. 11 oz. (.77 kilo)
Carrying Case for Above
Catalog No. 901
|