AEMC 1250N Data Sheet

Hand-cranked Megohmmeter Model 1210N (pdf) 12/05 Rev. 03

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The AEMC®Model 1250N is a compact,
self-contained, hand-cranked True
Megohmmeter

®

. This practical and
dependable instrument is designed for
a broad range of plant and field service
applications, such as acceptance
testing and preventive maintenance
of wiring, cables, switchgear and
motors. The easy hand-cranked
operation provides a steady, DC
voltage output across the entire range
for consistently reliable readings. The
Model 1250N has three test voltages
for insulation resistance testing: 250V,
500V and 1000V. Test voltages are
generated in full across the entire
measurement range.

The Model 1250N incorporates a
built-in, sealed alternator and constant
DC voltage circuit to provide a very
stable resistance reading. The

megohmmeter is ruggedly built, with a
safety-yellow cast aluminum case,
aluminum lid and polycarbonate front
panel. The Model 1250N is designed
for harsh, heavy-duty use. An O-ring
seal between the front panel and
case protects the unit against water
and dust. The crank folds against the
unit for storage.

This analog instrument has a unique
auto-ranging feature which expands
the scale ten times: when the pointer
reaches near the end of scale, the
auto-ranging feature activates,
returning the pointer to the beginning
of the scale with the x10 red LED
indicator on.

Insulation resistance is indicated with
a rugged taut-band meter movement
on a logarithmic scale. The indicator

scale is large and easy-to-read,
and has direct-reading on all ranges.
A green LED on the front panel
illuminates when the proper crank
speed is attained, indicating the
presence of the selected output.
The Model 1250N has four terminals
including a guard terminal and
an instrument ground terminal for
user safety.

The Model 1250N is supplied with a
carrying strap with lead pouch, a full
complement of test leads, clips and
test probe to perform any test.

Hand-cranked Megohmmeter
Model 1250N

Hand-cranked Megohmmeter Model 1210N (pdf) 12/05 Rev. 03

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MODEL 1250N

ELECTRICAL

Power Source Hand-cranked, heavy duty brushless alternator and

solid state rectification and amplification

for stable voltage; test voltage reached at 140rpm (approx)

INSULATION TESTS
Test Voltage 250V

11 to 11MΩ; 111 to 500MΩ

(Auto-Ranging) 500V

11 to 11MΩ; 111 to 500MΩ

1000V 10 to 110MΩ; 110 to 5000MΩ

Short Circuit Current 5mA (approx)
Accuracy 2% of Full Scale Length
Automatic Discharge 8s/µF
Charging Time 250V 0.2s/µF

500V 0.5s/µF

1000V 0.5s/µF

MECHANICAL

Scale Direct reading on MΩ and voltage scales; 3" (76mm), black on white
Test Voltage Indicator Green LED indicates proper test voltage and crank speed
Auto-Range Indicator Red LED indicates Auto-Range; multiply MΩ readings x 10
Dielectric Test 2000V, 50/60Hz, between (–), (+), and ground terminals
Meter Movement Rugged taut band suspension
Dimensions 4.7 x 4.7 x 5.1" (120 x 120 x 130mm)
Weight 3.3 lbs (1.5kg)
Case Cast aluminum alloy case and lid painted safety-yellow,

with heavy duty gray polycarbonate front panel;

O-ring seal between front panel and case;

sealed against water and dust; folding crank

Terminals Guard “+” Line (red); “-” earth (black); guard (blue), and ground;

accept standard 4mm banana plugs or spade lugs

SAFETY

Safety Rating EN 61010-1, 600V, Cat. II; 1000V, Cat. I

Double Insulation Yes

CE Mark Yes

Specifications

Features

• True Megohmmeter

®

• Test voltages of 250V, 500V

and 1000V

• Insulation measurements to 5000MΩ

• LED indicates constant voltage

output and proper cranked speed

• Automatic discharge when

measurement is finished

• Auto-Ranging — dual scale operation

for better sensitivity and easier
readings

• Designed for harsh environments:

marine, mining, heavy-duty field,
industrial and military use

• Extra rugged cast aluminum case,

O-ring sealed against rain, water
and dust; aluminum lid

• Compact, self-contained package;

folding crank

• Large direct-reading scale

• Double Insulation

• CE Mark

Applications

• Acceptance testing and preventive

maintenance

• Test motors, cables, switchgears and

electrical wiring installations

• Continuity checks

• Check domestic and industrial

contracting

Hand-cranked Megohmmeter Model 1210N (pdf) 12/05 Rev. 03

Technical Assistance [phone] www.aemc.com 3 of 4

ORDERING INFORMATION CATALOG NO.

Megohmmeter Model 1250N (Hand-cranked, 250V, 500V, 1000V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cat. #1326.02

Includes carrying strap with lead pouch, three color-coded leads, ground lead, two alligator clips,
test probe and user manual

Test leads, clips and test probe are included

Detachable soft carrying case.

The case attaches to the carrying strap.

1. Line (–) terminal Black

2. Guard Terminal Blue

3. Earth (+) terminal Red

4. Instrument ground terminal
for user safety

5. Green (1250N) LED indicates proper
crank speed and output voltage

6. Fold-away handle

7. Mechanical zero adjustment screw

8. Range selector switch

9. Red LED illuminates when reading
needs to be multiplied
10 to obtain the true value
(MΩ, kΩ, Ω ranges)

10. Security finger rest isolates
users hand from terminals while
facilitating a firm grip during
an operation

Hand-cranked Megohmmeter Model 1210N (pdf) 12/05 Rev. 03

Technical Assistance [phone] www.aemc.com 4 of 4

Contact Us

United States & Canada:

Chauvin Arnoux

®

, Inc.

d.b.a. AEMC

®

Instruments
200 Foxborough Blvd.
Foxborough, MA 02035 USA
[phone] • Fax [phone]
www.aemc.com

Customer Support – for placing an order, obtaining price & delivery:

[e-mail]

Sales Department – for general sales information:

[e-mail]

Repair and Calibration Service – for information on repair & calibration, obtaining a user manual:

[e-mail]

Technical and Product Application Support – for technical and application support:

[e-mail]

Webmaster – for information regarding www.aemc.com:

[e-mail]

South America, Central America, Mexico, Caribbean, Australia & New Zealand:

Chauvin Arnoux

®

, Inc.

d.b.a. AEMC

®

Instruments
15 Faraday Drive
Dover, NH 03820 USA
[phone] • Fax [phone]
[e-mail]
www.aemc.com

All other countries:

Chauvin Arnoux SCA
190, rue Championnet
75876 Paris Cedex 18, France
33 1 44 85 45 28 • Fax [phone]
[e-mail]
www.chauvin-arnoux.com