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Introduction
In response to ever growing demands for safer and more accurate methods
of testing circuit breakers, Weis has developed the self powered MM100
portable microhm meter. It is used for measurement of resistance (µW)
by injecting a heavy current through a breaker contact or load carrying
joint.
A regulated 100A continuous or pulsed current output is used for regular
resistance measurement. Alternatively a high current pulsed output (1200A
maximum at 4V) allows for testing of the latest arcing and main contacts
that require more than 500-600A to determine the difference between them,
as well as to see if they are able to carry such a current.
As a stand-alone unit, static testing can be performed with a direct
readout on a built in LCD meter. When used in conjunction with the Weis
SA100 switchgear analyser / breaker tester (having a travel input for
breaker mechanism movement), a dynamic microhm test can be made that will
give detailed information about the state of fixed contact surfaces, moving
contact surfaces, main contact, arcing contact and the complete current
circuit of the breaker in every step during a close-open operation.
Specifications
| MEASUREMENT OUTPUT |
| Current: |
Pulsed 1200A DC maximum
(at 4V) dependant on loop impedance. Pulsed / continuous 100A
DC regulated (up to 6V). |
| No-Load Voltage: |
10V DC maximum. |
| Operation: |
1200A
pulse with 1 second duration.
100A
pulse with 2 second duration.
100A
continuous (no time limit). |
| Safety: |
Re-settable thermal /
magnetic circuit breaker. |
| Connectors: |
Heavy duty wing-nut. |
|
MEASUREMENT INPUT |
|
| Range: |
0 to 1.999 or 19.99mΩ (selectable). |
| Resolution: |
1 or 10µΩ (range selected). |
| Accuracy: |
1% of reading +/- 1 digit. |
| Voltage Sense: |
1 x voltage input from contact / joint. |
| Connectors: |
4mm safety socket. |
| OUTPUTS |
|
| Analogue: |
3 x 0 to 10V DC conditioned outputs representing
measured Voltage Drop, Current Level and Microhms. 1 x Calibrate
for calibration check. |
| Connectors: |
1 x Calibrate for calibration check. |
| GENERAL SYSTEM |
|
| Back-lit 3½
digit LCD for readout of Ohms or Amps (switch selectable). Current
On lamp indication (red). Unit Armed lamp indication (green).
Trigger In (volt free contact) for Dynamic Microhm Test (SA100
required) and Trigger Out (15V logic). Intermittent audible during
continuous operation.
Operate’ push button for 100 / 1200A pulse or 100A
continuous with stop, modes of operation (static testing). Rotary
selector switch for Off / 100A (1.999mΩ range) / 100A (19.99mΩ
range) / 1200A (1.999mΩ range). LED indicators for Fault,
Over Current, Battery Low and Charging. Multipurpose accessory
socket for in-car charging, remote meter, power out, trigger in
and trigger out. |
| OPERATING VOLTAGES |
|
| Prime Power: |
Internal sealed rechargeable batteries. |
| Recharge Power: |
100 to 350V DC, 88 to
264V AC, In-Car 12V DC @ 3A (negative earth). |
| Burden: |
<100VA load. |
| ENVIRONMENTAL |
|
| Operating Temperature: |
-20ºC to 55ºC (-4ºF to 131ºF). |
| Humidity: |
0 to 97% RH non-condensing. |
| Isolation: |
2kV rms for 1 minute (input / output to
ground). |
| Surge Withstand Transient: |
To IEC 801-5. 5kV, 1.2/50mSec,
0.5 joule. Common Mode: Severity level class 4. Series Mode: Severity
level class 3. |
| RF Immunity: |
To IEC 801-3 level 3. 10V/m 26-1000MHz. |
| Emissions: |
To EN50081-1: 1992. |
| MECHANICAL DETAILS |
|
| Case: |
500mm wide.
330mm
high.
380mm deep. |
| Weight: |
19.6kg. |
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