Megger DLRO200-115 Specifications

Digital Low Resistance Ohmmeter

DLRO 200-115

Digital Low Resistance Ohmmeter

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Small and weighs less than 32 lbs (14.5kg)

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Test currents from 10 A to 200 A d.c.

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Filtered direct current output eliminates

magnetic transients

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0.1 µ best resolution

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On board memory for up to 300 test

results and notes

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RS232 port to download stored results

or for real time output to a printer

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Supplied complete with 16 ft. (5m)

test leads and download software

DLRO 200-115

DESCRIPTION

The DLRO200-115 is designed to check and measure contact
resistance in high voltage circuit breakers, disconnecting switches
(isolators), busbar joints, or for any low resistance measurement.

The test set accurately measure resistances ranging from 0.1µΩ to
1Ω, at high currents.

This versatile instrument can provide test currents from
10 amps up to 200 amps, subject to the load resistance
and supply voltage. For those applications that demand a smooth
dc current, the DLRO200-115 has extra filtering on the output to
reduce mains frequency ripple and can drive 200 amps through a
total current loop resistance of
11 milliohms. The filtered output of the DLRO200-115 also
eliminates magnetic transients that could inductively trip a breaker’s
control (bus differential relay), if left in the test circuit.

The unique design allows the weight and size of the DLRO200­115 to be kept to a minimum; the instrument weighs less than 32
lbs. (14.5 kg). This small size plus a water/dust ingress rating of
IP54 makes the test set equally at home in the workshop, on the
production floor or in the field.

As many as 300 sets of results may be stored in the test set’s
on-board memory for later download to a PC or may be sent
directly to a printer via the RS232 port. You may also add notes
to any stored result by using the on-board alphanumeric keypad,
thereby making later identification of results easier to determine.

As well as adding notes to stored results, the alphanumeric keypad
allows you to set the test current directly by keying in the value
required. The DLRO200-115 will check the continuity of the test

circuit, and will quickly ramp the test current up to the desired
level. The keyboard is also used to set upper and lower limits for
the result and to prevent the use of excessive currents by setting an
upper limit to the allowable test current.

The DLRO200-115 uses a four terminal measurement technique to
cancel the resistance of the test leads from the measurement.

The test set operates in one of three modes, which are simply
selected from the on-screen menu.

CONTINUOUS mode is provided for users who wish to monitor
a resistance over a period of time. Connect the test leads, select the
test current and press the TEST button. The DLRO200-115 will
pass a current continuously, and measure the load resistance at 2
second intervals, until the test button is pressed to stop the test or
the test circuit is interrupted.

In NORMAL mode you connect the leads, select the test current
and press the TEST button. The test current will ramp up to the
desired level, hold for 2 seconds and then ramp down. The whole
process takes approximately
10 seconds.

In AUTO mode select the desired current, connect the current leads
and press the TEST button. The TEST lamp will flash to show
that the DLRO200-115 is ready to carry out a test. As soon as
the potential leads are connected, a test will start. To repeat a test,
simply break contact with the voltage probes and remake contact.

Measuring individual joints in a busbar is a good example of the
convenience to be gained by using AUTO mode. The two current
leads are connected to the ends of the busbar. They will remain

DLRO 200-115

Digital Low Resistance Ohmmeter

connected there until all tests have been completed. When the
voltage leads make contact across a joint, the DLRO200-115 detects
that all four leads are connected, carries out a test and stops. When
you move to the next joint the DLRO200-115 detects the already
completed circuit automatically and carries out the next test, and
so on until all joints have been tested. The results may be stored
automatically and may be recalled to the display or downloaded for
review.

SPECIFICATIONS

Measurement:
Range: 0.1 µΩ to 999.9 mΩ

(Subject to supply voltage and leads used)

Accuracy:

Voltage: ±0.5% ± 0.1 mV

Current: ±0.5% ± 0.1 A

Resistance: Better than 1% from

100 µΩ to 100 mΩ

Current Lead Resistance (Megger supplied leads)

2 x 16 ft (5 m) 25 mm

2 x 16 ft (5 m) 50 mm

2 x 33 ft (10 m) 70 mm

2 x 49 ft (15 m) 95 mm

Maximum Continuous Test Time

More than 10 minutes at 200 A @ 68° F (20º C) ambient.

Power Supply
for full output (additional smoothed):

100 to 130 V 50/60 HZ with a load

less than 11 mΩ including current leads

2

current leads 8 mΩ

2

current leads 4 mΩ

2

current leads 5.4 mΩ

2

current leads 6 mΩ

Test Modes: Manual, Auto, Continuous.

Test Time: 10 seconds NORMAL /AUTO mode.

Refreshed every 2 seconds in CONTINUOUS
mode
Display: Large, high resolution backlit liquid crystal
display
Warnings Current flowing: - LED. Other warnings are
shown on the lcd display.
Data Transfer Real time or batch download via RS232
using Download Manager.

Storage Capacity:
300 result sets and memo, battery backed

for 10 years.

Memo field: 160 characters max.

Test Current
Range: Filtered direct current; 10 A to 200 A d.c.
Accuracy: ±2% ±2 A
Voltmeter input
impedance: >200 kΩ
Hum rejection: 5 V rms 50 Hz/60 Hz

Temperature
Operation: 14 to +122º F (-10 to +50º C)
Storage: -13 to 149º F (-25 to +65º C)
Calibration: 68° F (20º C)
Co-efficient: <0.05% per º C
Max. Humidity: 95% RH non-condensing
Maxi Altitude: 6562 ft. (2000 m)

Safety: IEC61010 – (1995)

EMC: EN61326 annex A (heavy industrial)

Dimensions: 16.4 x 9.84 x 10.63 in.

(410 x 250 x 270 mm)

Weight: 31.97 lbs. (14.5 kg) excluding test leads

ORDERING INFORMATION

Item (Qty) Cat No.

DLRO200-115 High Current Digital Low Resistance Ohmmeter
115 V (English QWERTY keyboard) DLRO200-115 E

Included Accessories

16 ft. (5 m) Lead set comprising 2 x 25 mm2
current leads with clips and 2 potential

leads with clips 6220-787
Download Manager 6111-442
User Guide on CD-ROM 6172-763
RS232 download cable 25955-025
Quick Start Guide (English) 6172-782

UK

Archcliffe Road, Dover
CT17 9EN England
T [phone]
F [phone]
[e-mail]

UNITED STATES

4271 Bronze Way
Dallas, TX 75237-1019 USA
T 1 800 723 2861 (USA only)
T [phone]
F [phone]
[e-mail]

Item (Qty) Cat No.

Optional Accessories at extra cost

16 ft. (5m) Lead set in bag comprising: 6220-755
2 x 50mm2 current leads with clamps and
2 x potential leads with clips
49 ft. (15m) Lead set comprising 2 x 95 mm2
current leads with clamps and
2 x potential leads with clips 6220-757
33 ft. (10m) Lead set comprising 2 x 70 mm2
current leads with clamps and
2 x potential leads with clips 6220-756

OTHER TECHNICAL SALES OFFICES

Valley Forge USA, College Station
USA, Sydney AUSTRALIA, Täby
SWEDEN, Ontario CANADA, Trappes
FRANCE, Oberursel GERMANY, Aargau
SWITZERLAND, Kingdom of BAHRAIN,
Mumbai INDIA, Johannesburg SOUTH
AFRICA, and Chonburi THAILAND

Registered to ISO 9001:2000 Reg no. Q 09290

Registered to ISO 14001 Reg no. EMS 61597

DLRO200-115_DS_en_V04

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Megger is a registered trademark