The MS-1A test unit has a patented circuit consisting of a continuously variable autotransformer which supplies a Multi-Amp output transformer, thus providing stepless control of the output current. Integral metering, timing and control circuitry are included. The unit is housed in a convenient suitcase-type enclosure for easy portability. The MS-1A will test time-current characteristics of motor overload relays and molded case circuit breakers rated up to 100 amperes by simulating overloads up to 300% of their rating. Auxiliary applications include testing of in-line motor cut-outs, fuse links, meters and rationing current transformer.
•50 hertz units are equipped to operate from 120 volts, 50 hertz, single phase. For other
|Rating ||0.6 kVA |
|Input ||120 volts, 60 hertz*, single phase |
|Output ||Continuously adjustable in four ranges lo meet a variety of test |
- 0 - 140 volts at 4.5 amperes
- 0 - 24 volts at 25 amperes
- 0 6 volts at 100 amperes
- 0 - 3 volts at 200 amperes
|Ammeter ||A large, easily read instrument with 3½ inch scale: |
- Scales: 5110/25
- Ranges (switch selected): 0-2.5/5/10/25/50/100/250/500 amperes
|Timer ||A synchronous motor-driven digital mechanism accurate to ± 0.5* |
second. Measures elapsed time of the test from 0.1 second to 9999.9** seconds. Push-button reset.
|Housing ||Molded public, high strength suitcase type enclosure with easy to |
carry handle. Storage space is provided for test leads.
|Dimensions ||Height: 9 inches; Width: 14½ inches; Depth: 9 inches |
|Weight ||Net: 35 pounds; Shipping: 42 pounds |
|Test Leads ||Two No. 22 timer leads each 5 feel long. These leads are used |
to connect the binding posts on the MS-1A labeled CONTACTS to
the contacts of the device under test which will open when the
Two No. 4 high current lead., each 5 feet long. These cables are
used to connect the output terminals of the MS-1A to the current
element of the device under test.
input voltages use a suitable 1.0 kVA step-down transformer.
••S/N 5070 and up. Earlier units are accurate to ± 1 second and measure from
1 second to 999 seconds.