Simpson 260 8XPI User Manual

Simpson 260® Series 8XPI

Volt-Ohm-Milliammeter

INSTRUCTION MANUAL

About this Manual

To the best of our knowledge and at the time written, the information contained in
this document is technically correct and the procedures accurate and adequate to
operate this instrument in compliance with its original advertised specifications.

Notes and Safety Information

This Operator’s Manual contains warning headings which alert the user to check
for hazardous conditions. These appear throughout this manual where applicable,
and are defined below. To ensure the safety of operating performance of this in­strument, these instructions must be adhered to.

Warning, refer to accompanying documents.

!

Caution, risk of electric shock.

!

This instrument is designed to prevent accidental shock to the operator when
properly used. However, no engineering design can render safe an instrument
whick is used carelessly. Therefore, this manual must be read carefully and com­pletely before making any measurements. Failure to follow directions can result in
ser ious or fatal accident.

Shock Hazard: As defined in American National Standard, C39.5, Safety
Requrements for Electrical and Electronic Measuring and Controlling Instrumen­tation, a shock hazard shall be considered to exist at any part involving a potential
in excess of 30 volts RMS (sine wave) or 42.4 volts DC or peak and where a
leakage current from that part to ground exceeds 0.5 milliampere, when mea­sured with an appropriate measuring instrument defined in Section 11.6.1 of ANSI
C 39.5.

Technical Assistance

SIMPSON ELECTRIC COMPANY offers assistance Monday through Friday
7:30 am to 5:00 pm Central Time by contacting Technical Suppor t or
Customer Service at [phone].
Internet: http://www.simpsonelectric.com

Warranty and Returns

SIMPSON ELECTRIC COMPANY warrants each instrument and other ar ticles
manufactured by it to be free from defects in material and workmanship under
normal use and service, its obligation under this warranty being limited to making
good at its factory or other article of equipment which shall within one (1) year
after delivery of such instrument or other article of equipment to the original pur­chaser be returned intact to it, or to one of its authorized service centers, with
transportation charges prepaid, and which its examination shall disclose to its
satisfaction to have been thus def ectiv e; this warranty being expressly in lieu of all
other warranties expressed or implied and of all other obligations or liabilities on
its part, and SIMPSON ELECTRIC COMPANY neither assumes nor authorizes
any other persons to assume for it any other liability in connection with the sales of
its products.

This warranty shall not apply to any instrument or other article of equipment which
shall have been repaired or altered outside the SIMPSON ELECTRIC COMPANY
factory or authorized service centers, nor which has been subject to misuse, neg­ligence or accident, incorrect wiring by others, or installation or use not in accord
with instructions furnished by the manufacturer.

®

is a Registered Trademark of the Simpson Electric Company.

260

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Contents

1. INTRODUCTION ..............................................................................5

1.1 General Description ........................................................................... 5

1.2 Overload Protection ...........................................................................5

1.2.1Fuses .........................................................................................6

1.3 Internal Batteries................................................................................6

1.4 Overload Circuit Test ..........................................................................7

1.5 Printed Circuit ....................................................................................7

1.6 Adjust-A-Vue Handle ..........................................................................7

1.7 Test Leads ..........................................................................................7

1.8 Technical Data....................................................................................7

1.9 Definition Of Accuracy........................................................................9

1.10 Safety Considerations........................................................................ 9

1.11 Audio Alarm .......................................................................................9

1.12 Accessories........................................................................................ 9

1.13 Additional Accessories .....................................................................10

2. INSTALLATION ............................................................................... 11

2.1 Unpacking and Inspection................................................................11

2.2 Warranty...........................................................................................11

2.3 Shipping ........................................................................................... 11

2.4 Power Source Requirements ........................................................... 11

2.5 Operating Position............................................................................11

3. OPERATION ................................................................................... 12

3.1 Safety Precautions ...........................................................................12

3.2 Operational Items and Features ......................................................13

3.4 Polarity Reversing ............................................................................15

3.5 Measurement of Unknown Voltage or Current ................................. 15

3.6 Test Leads ........................................................................................15

3.7 DC Voltage Measurement ...............................................................15

3.8 AC V oltage Measurement ................................................................17

3.9 Output V oltage Measurement ..........................................................19

3.10 Decibel Measurement (-20 to +50 dB)............................................. 20

3.11 Direct Current Measurement............................................................21

3.12 Zero Ohms Adjustment .................................................................... 22

3.13 Measuring Resistance .....................................................................23

3.14 Resistance Measurement of Semiconductors ................................. 23

1.13.1 Accessory DC High Voltage Probes ................................................. 10

1.13.2 Accessory AC High Voltage Probe ................................................... 10

1.13.3 Amp-Clamp Model 150-2.................................................................. 10

3.7.1 DC Voltage Measurement 0-250 mV Range .................................... 15

3.7.2 DC Voltage Measurement 0-2.5 Through 0-250V Range ................. 16

3.7.3 DC Voltage Measurement 0-500V Range ........................................ 16

3.7.4 DC Voltage Measurement 0-1000V Range ...................................... 17

3.8.1 AC Voltage Measurement 0-2.5 Thru 0-250V Range ....................... 17

3.8.2 AC Voltage Measurement 0-500V Range ......................................... 18

3.8.3 AC Voltage Measurement 0-1000V Range....................................... 19

3.11.1 Direct Current Measurement 0-50µA Range................................... 21

3.11.2 Direct Current Measurement 0-1mA Through

0-500mA Range .............................................................................. 21

3.11.3 Direct Current Measurement 0-10A Range..................................... 22

Continued.

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Contents Continued

3.15 Continuity Tests ................................................................................24

4. OPERATING SERVICING ................................................................. 24

4.1 Removing the Instrument Case ....................................................... 24

4.2 Battery and Fuse Replacement ....................................................... 25

4.3 Fuse Protection ................................................................................25

4.5 Care .................................................................................................26

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1. INTRODUCTION

1.1 General Description

The Simpson Volt-Ohm-Milliammeter 260 Ser ies 8XPI, (hereafter referred to as
the 260 or the Instrument) is a rugged, accurate, compact, easy-to-use instrument
equipped with mirrored dial to eliminate parallax. The Instrument can be used to
make accurate measurements of AC and DC voltage, direct current, resistance,
decibels, and Output Voltage. The Output Voltage function is used for measuring
the AC component of a mixture of AC and DC voltage. This occurs primarily in
amplifier circuits.

New Features in the 260-8 are:

0-25V AC/DC Range
Continuity Test Alarm
Individual Dual Jacks for the 500 V AC/DC and 1000 V AC/DC Ranges
High Impact Case (Yellow)

1.2 Overload Protection

All the ranges, with exception of 1V, 200 mV , 500/1000 V A C and DC are protected
by an electronic overload protection system. The protection is from the usual
overloads that would damage the V OM. A transistorized circuit senses the voltage
drop across the indicating instrument and actuates a relay when the voltage reaches
approximately 3 to 4 times rated full scale voltage . Sensing of the voltage drop is
by means of a bridge network so that overload protection is provided regardless of
polarity. The relay operates at a uniform percent of overload since the indicating
instrument circuit is common to all ranges. When actuated by an overload, the
relay contacts, which are in the -COMMON CIRCUIT, latch open until the reset
button on the front panel is depressed.

!

Due to its sensitivity to overloads, the electronic ov erload protection rela y incorpo­rated in the 260 is susceptible to electrostatic fields from high potentials or tran­sients either in the circuit being measured or in nearby circuitry.

Do not assume the relay to be faulty if it trips out without apparent cause. It may
be indicating a dangerous condition such as excessive circuit-to-ground (floating)
voltage being applied to the Instrument.

Avoid loading the Instrument or its test leads until certain that excessive circuit-to­ground voltage does not exist.

a. A switch that is opened when the relay latches, opens the relay circuit and

prevents continuous battery drain. This condition occurs when the reset but­ton has been pressed so that the VOM is operational; the protection circuit
draws less than the shelf life drain of the battery.

b. Since the 9 V battery is used for both the R X range and the protection circuit,

the VOM is designed to allow the protection circuit to function normally as
long as the R X range can be set to zero and an Alkaline battery is used.

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c. The 1 and 2 Amp fuses in the input circuit add protection to the relay contacts.

Some overload conditions may cause the fuses to burn out as well as open
the relay contacts.

d. When an overload of sufficient magnitude is applied to the VOM, the reset

button will “pop up” approximately 3/16 inch above the surface of the panel.
T o reset the VOM for normal operation, first remove the overload and depress
the button. If the ov erload remains connected to the Instrument, resetting the
overload protection reset button will not connect the VOM input circuit.

In addition to the overload protection circuit, a pair of diodes protects the indicat­ing instrument circuit. The diode limits the current through the coil in case of
overload.

1.2.1 Fuses

Basic overload protection is provided by a small ine xpensiv e and easily obtainable
3 AG type, 1 Amp, quick-blow fuse. This fuse is rated to interrupt circuit voltages
up to 250V. A supplemental high energy fuse is provided for additional protection
from severe overloads. This fuse is the Bussman Type BBS 2A 600V with an
interrupt capacity of 10,000 Amps AC. The Littlefuse Type BLS 2A 600V ma y also
be used.

NOTE: If the 260 fails to indicate a reading, the 1 or 2 Amp fuse may be burned
out. (Refer to paragraph 4.2 for fuse replacement.) Use only the specified fuse
type. The 0-10 A range is not fused. The shunt connects directly to the -10 A and
+10 A jacks.

The relay, fuse and diodes will prevent serious damage to the Instrument in most
cases of accidental overload. However, no overload protection system is com­pletely foolproof and misapplication on high voltage circuits can damage the In­strument. Exercise care and caution to protect both the user and the Instrument.

1.3 Internal Batteries

Two batteries are in the ohmmeter circuits, a NEDA 13F “D” cell that furnishes 1.5
V for the R X 1 and R X 100 ranges and a NEDA 1604A Alkaline battery that
furnishes 9 V for the R X 10,000 range . The 1.5 V “D” cell is held in place with two
spring clips which also serve as battery contacts. The polarity symbols for the “D”
cell are marked near the battery contacts. The 9 V battery is held in place with a
spring clip, but contact is made with a separate connector that is polarized. Al­ways observe correct polarity when replacing the 1.5 V “D” cell.

!

The 9 V battery must be installed and tested before the Instrument is ready for
use. Perform the overload test described in Par ag raph 1.4 to ensure proper o ver­load circuit operation prior to using the Instrument.

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1.4 Overload Circuit Test

a. Set the range switch to R X 10,000 position and the function switch to the -DC

position.

b. Plug the black test lead into the -COMMON jack terminal and touch the other

end of the test lead to the +10 A input terminal. (The relay reset b utton should
rise, indicating that the overload circuit is in working condition.)

NOTE: No damage will occur to the Instrument as a result of this test.

1.5 Printed Circuit

Most of the component parts are mounted on a printed circuit board which simpli­fies assembly and maintenance, thus extending the useful life of the Instrument.

1.6 Adjust-A-Vue Handle

A carrying handle is attached to the Instrument case. The handle may be used to
support the Instrument in a convenient sloping position for easy viewing. The
case can also be placed in either a vertical or horizontal position. The horizontal
position is preferable f or greater accuracy since the Instrument is calibrated in this
position.

1.7 Test Leads

Each Instrument is furnished with one pair (Catalog Number 00125) of probe type
test leads (one red and one black, each 48 inches long) for all applications of the
Instrument. These test leads hav e elbow prods on one end to connect the leads to
the recessed jacks on the Instrument front panel. The probe tips at the opposite
end have threaded shoulders to accept the screw-on insulated alligator clips (fur­nished with the test leads) or the 5000 volt test probe(s) to extend the Instrument
AC or DC voltage range . The test leads and the insulated alligator clips are rated
for the voltage and current ranges available on the 260. Maximum ratings are
1000V AC or DC or 10 DC Amps. These ratings for the test leads must not be
exceeded in any application.

1.8 Technical Data

Table 1-1. Technical Data

1. DC VOLTS:
Ranges: 0-1-2.5-10-25-50-250-500-1000V
Sensitivity: 20,000 ohms per volt

2. DC MILLIVOLTS:
Range: 0-250mV
Sensitivity: 20,000 ohms per volt

3. AC V OLTS:
Ranges: 0-2.5-10-25-50-250-500-1000V
Sensitivity: 5,000 ohms per volt

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4. OUTPUT VOLT AGE:
(AC):
Ranges: 0-2.5-10-25-50-250 (limited to 350 VDC)

5. DC MICROAMPERES:
Range: 0-50µA
Voltage Drop: 250mV

6. DC MILLIAMPERES:
Ranges: 0-1-10-100-500 mA
Voltage Drop (Approx.): 250 mV, 255 mV, 300 mV, 500 mV

7. DC AMPERES:
Range: 0-10A
Voltage Drop (Approx.): 255 mV

NOTE: The 10A range is not internally fused.

8.

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egnaR000,2-0 Ω 000,002-0 Ω M02-0 Ω

gnidaeRretneC21 Ω 0021 Ω 000,021 Ω

egatloVtiucriCnepOlanimoNV5.1V5.1V9

tnerruCtiucriCtrohSlanimoNAm521Am52.157 µA

9. *ACCURACY:
DC Voltage Ranges: 2% of Full Scale
DC Current:
0-50 µA Range: 1.5% of Full Scale
Other Ranges: 2% of Full Scale
**AC Voltage Ranges: 3% of Full Scale
Frequency Response: Referenced to 100 Hz (Figures 3-2 and 3-3)
Resistance Ranges:
R X 1: 2.5° of Arc
R X 100: 2° of Arc
R X 10,000: 2° of Arc

10. DECIBELS:
Range: -20 to +10 dB, -8 to +22 dB, 0 to +30 dB, +6 to

+36 dB, +20 to +50 dB

Reference Level: With zero dB power level equal to 1 mW across a

600 line.

11. BATTERIES:
Voltage: 1.5V, 9V
NEDA No.: 13F, 1604A

12. FUSE: F1 1A, 250V , type 3AG, quic k-acting Littlefuse T ype

312001, F2 2A, 600V Littlefuse Type BLS or 2A
600V, Bussman Type BBS.

13. TEST LEADS: 1 red, 1 black, 48" long.

14. SIZE: 5 1/4" x 7" x 3 1/8" (13.34 x 17.78 x 7.94 cm)

15. WEIGHT: 2 1/4 lbs (1.02 Kg)

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16. ***RATED CIRCUIT-TO

-GROUND VOLT AGE: 1000V AC/DC Max.

* Accuracies specified are for the 260 in a horizontal position.
** Responds to the average value of an AC current, and is calibrated to indicate

the RMS value of a pure sine wave.

*** Per ANSI C39.5 April 1974: “The specified voltage with respect to ground,

which may be safely and continuously applied to the circuit of an Instrument.”

1.9 Definition Of Accuracy

The voltage and current accuracy of this Instrument is commonly expressed as a
percent of full scale. This should not be confused with accur acy of reading (indica­tion). F or example, +2% of full scale on the 10 v olt range allows an error of 0.20V
at any point on the dial. This means that at full scale, the accuracy reading would
be 2%, but at half scale it would be 4%. Therefore, it is adv antageous to select
a range which gives an indication as near as possible to full scale.

1.10 Safety Considerations

This Operator’s Manual contains cautions and warnings alerting the user to haz­ardous operating and service conditions. This inf ormation is flagged by CA UTION
or WARNING symbols throughout the publication, where applicable, and is de­fined on the inside front cover under “Notes and Safety Information.” Adhere to
these instructions in order to ensure the safety of operating and servicing person­nel and to retain the operating conditions of the Instrument.

1.11 Audio Alarm

The 260 Audio Alarm transducer will emit an audio sound when the continuity of a
circuit being tested is completed.

!

No Circuit Continuity Tests are to be made with electrical power “ON.” Turn “OFF”
all electrical power.

1.12 Accessories

Table 1-2. Items and Accessories Furnished with this Instrument.

Quantity Description Number

1 Test Lead Set - one red and one black (48” long) 00125

*1 1.5 Volt, D Cell, NEDA 13F
*1 9.0 Volt Cell, NEDA 1604A

2 1 Amp, 250V Fuse, Littlefuse Type #312001
1 2A, 600V Fuse, Littlefuse Type BLS (or Bussman

1 Operator’s Manual 6-115022

*Batteries are standard items replaceable at local retail stores

each with combination probe tip and removable
rubber-sleeved alligator clip.

Type BBS)

.

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