Actron CP7848 User Manual [en, es]

POCKET ELECTRICAL TESTER

10K	60			30		20		10		8	6 5 4
5K 200													3	2
	40
1K 100															1
							100			150
					50		20			30		200				CP7848
•mA					10		4			6		40	1050		•m
						2						8
														250V
V						+8	+12	+16	+18		+20		A		A
			0	V			CE		?
	A C	1		dB	-20		PLA	60%		G	D	+22	d	1
						RE					OO		B	0
								BAT						0dB:	AC V ADD
FUSE & DIODE											110%				RANGE	dB
														1mW
PROTECTION														600	10	0
															50	14
DC 10000 / V															250	28
AC 40000 / V															1000	40
					®									CP7848
by
								OFF
DC V					1000						1000				AC V
	250												250
50														50
2.5														10
	10													X1K
				250									X10
						1.5V			9V
	DCmA							BAT					OHM

OPERATING INSTRUCTIONS

Instrucciones en

Español e Inglés

GENERAL DESCRIPTION

The CP7848 Pocket Analog Tester is a rugged, accurate, easy to operate, compact instrument. The stable linear meter movement of the tester allow it to make accurate measurements of AC and DC voltages, DC currents in the milliamp range, resistance, and decibels. The tester uses the most modern components and circuit techniques de

signed		in a high	impact case.	If the tester is kept clean and
is	not	subjected to extreme		shock or	continuous vibration,
it	will	provide	many years of trouble		free service.

SPECIFICATIONS

ELECTRICAL

Range: 18 measuring ranges

DC voltage: 0 2.5 50 250 1000volts

AC voltage: 0 10 50 250 1000volts

DC current: 0 10 250mA

Resistance: OHM X10, OHM X1K

Decibel:

20dB to 62dB at AC volt ranges

Accuracies: DC V/A 4% Full Scale, AC V 5% Full Scale Resistance: 4 Arc of scale length

Sensitivity: 10,000 Ohms/VDC, 4,000 Ohms/VAC

BAT test:

1.5V, or 9V batteries

PHYSICAL

Function range switch: A 14 position switch located at the center of the tester. This switch is used to select the func tion and range to be measured.

Zero Adjuster: A thumbwheel adjustment located on the left side of the tester. The zero adjuster is used to zero the meter pointer when making resistance measurements.

Mechanical adjuster: A screw located directly below the center of the meter scale. The mechanical adjuster is used to set the meter pointer to the Zero mark at the left side of the black scale.

Negative ( ) jack: Plug in connector located at the lower left corner of the tester. The BLACK or negative( ) test lead is always inserted in this jack.

Positive ( ) jack: Plug in connector located at the lower right corner of the tester. The RED or positive( ) test lead is always inserted in this jack.

Power supply:	One 1.5V, size	AA	cell battery for Ohm
meter.
Size & Weight: 5	3/4 x 2 1/2	x 1	1/4 , 136g.

SAFETY PRECAUTIONS

1. Always visually inspect the tester, test leads, and circuit under test for damage prior to every use.

2.Turn off power and discharge any capacitors and induc tors prior to connecting or removing test leads from an electrical circuit or electronic equipment.

3.Always keep yourself isolated from an electrical circuit when making measurements. When possible use one hand to make measurements.

4.Never allow yourself to be grounded when making elec trical measurements. Stand on a rubber mat, wear dry clothing, use insulated test probes, and be careful of all

exposed metal when making electrical measurements.

5.Never hold tester when making electrical measurements. Place the tester on a clean insulated surface before mak ing any electrical measurements.

OPERATING INSTRUCTIONS

CAUTION ! When making voltage or current measure ments, form the habit of turning off all power to the cir cuit under test, and discharge any capacitors and induc tors. Connect the test leads at the desired points in the circuit and then turn on the power while taking readings. Turn off the power and discharge any capacitors and in ductors, before disconnecting the test leads from the cir cuit.

PRELIMINARY ADJUSTMENTS

Adjust the meter pointer to the Zero mark at the left side of the black scale before making any measurements. First, check to see if the meter pointer indicates Zero at the ex

treme left end of the	black scale. If it is	off Zero,	use a
small screwdriver to	turn the mechanical	adjuster	screw

on the meter movement slowly CW (clockwise) or CCW

(counterclockwise) until the		meter pointer	is exactly over
the Zero mark.
INTERNAL BATTERY CHECK
Important:	A 1.5V AA	cell battery must be installed
before using	the CP7848.	(See Battery	Replacement)

In order to check the battery condition, insert the black test lead into the ( ) negative jack, and insert the red test lead into the ( ) positive jack. Set the function range switch to the OHM X10 position and touch the ends of the two test leads together. Rotate the Zero Adjuster thumbwheel lo cated on the left side of the tester until the pointer indi

cates Zero on the	green ohms scale. If the pointer	cannot
be brought to the Zero mark, replace the 1.5 volt size		AA
cell battery. (See	Battery Replacement)

OPERATING SUGGESTIONS

1.Set the range switch to the proper position before tak ing any measurement.

2.Never apply more voltage or current than the amount noted in each position.

3.When the voltage or current to be measured is not known,

always start with the highest range in each case.

4.If the meter pointer is in the lower half of the scale and falls within the range of a lower function range switch position, then rotate the function range switch to the lower range for greatest accuracy.

5.If none of the tester functions work at all, check the fuse

located inside the tester on	the printed circuit board. If
the fuse is blown, replace	it. (See Fuse Replacement)

6.Avoid placing the tester in a place where severe vibra tion is encountered; Do not store it in excessively hot or damp places!

7.Do not check resistance when voltage or current is present in the circuit.

8. Discharge a capacitor before measuring it.

9. When the tester is not in use, keep the function range switch in the OFF position. This provides a direct short across the meter movement, stabilizing the needle for minimum needle bounce when transporting the tester.

10. If	excessive voltage or current is accidentally applied
on a	certain range, disconnect the leads from the circuit
as quickly as possible. Check the tester operation on that
range by applying an appropriate input. If the tester does
not operate properly, check the fuse; if it is blown, re
place	it. (See Fuse Replacement)

OPERATING PROCEDURES

DC VOLTAGE MEASUREMENT

1.Read all SAFETY PRECAUTIONS.

2.Set the function range switch to the appropriate DC volt age range. If the voltage is unknown, use the highest range.

3.Insert the BLACK test lead into the ( ) negative jack and the RED test lead into the ( ) positive jack.

4.If the polarity of the circuit to be tested is known, con nect the BLACK probe to the ( ) negative voltage side of the circuit, and the RED probe to the ( ) positive voltage side.

5.If the polarity of the circuit to be tested is not known, connect the probes to opposite sides of the circuit and watch the meter pointer. If the meter pointer deflects to the left, reverse the probes. The RED probe will now be

connected to the ( ) positive voltage side.

6.Use the black scale for reading DC voltage measure ments.

DC CURRENT MEASUREMENT

1.Read all SAFETY PRECAUTIONS.

2.Set the function range switch to the appropriate DC mA

range. If the current is unknown, use the highest range.

3.Insert the BLACK test lead into the ( ) negative jack, and the RED test lead into the ( ) positive jack.

4. Using	the test	leads, connect the tester in series with
the circuit under test. If the meter pointer deflects to the
left,	reverse the	test probes.

5. Use the black scale for reading DC mA measurements.

AC VOLTAGE MEASUREMENT

1.Read all SAFETY PRECAUTIONS.

2.Set the function range switch to the appropriate AC volt age range. If the voltage is unknown, use the highest range.

3.Insert the BLACK test lead into the ( ) negative jack and the RED test lead into the ( ) positive jack.

4.Connect the RED and BLACK test probes to opposite

sides of the AC voltage source. (Polarity of test probes is unimportant on AC voltage.)

5.Use the red scale for 10V and 1000V AC voltage mea surements. Use the black scale for 50V and 250V AC voltage measurements.

DECIBEL

1.Read all SAFETY PRECAUTIONS.

2.Insert the BLACK test lead into the ( ) negative jack, and the RED test lead into the ( ) positive jack.

3.Set the function range switch to the appropriate AC volt

age range for the dB range you wish to measure.

4.For a function range switch setting of 10 AC V, read the dB directly from the bottom of the red scale in dB. For

other AC V settings of the function range switch, add the appropriate number of dB to the dB scale reading as noted on the chart at the lower right corner of the meter face.

RESISTANCE MEASUREMENT

1.Read all SAFETY PRECAUTIONS.

2.Turn off all power in circuit before making resistance measurements.

3.Set the function range switch to the appropriate OHM range. If the resistance is unknown, use the highest range.

4.Insert the BLACK test lead into the ( ) negative jack, and the RED test lead into the ( ) positive jack.

5.Touch the ends of the two test leads together. Rotate the Zero Adjuster thumbwheel located on the left side of the

tester until the pointer indicates Zero on the green ohms scale. If the pointer cannot be brought to the Zero mark, replace the 1.5 volt size AA cell battery. (See Battery Replacement)

6.Connect the test probes across the resistance to be measured.

7. Take a reading on the green Ω	scale and multiply it by
the multiplication factor indicated by the function range
switch. Multiply reading by 1K (1000Ω		) for the OHM 1K
position and, by 10 for the OHM 10 switch position. The
units for the OHM 10 position are ohms		Ω .

8. If there is little or no meter pointer movement from the
left side of the green			Ω	scale, rotate the function range
switch to a higher range in an effort to get a greater de
flection of the		meter	pointer. The most accurate reading
on	an ohmmeter	ranges		between the middle of the scale
and	Zero ohms.

BATTERY CHECK

1.Read all SAFETY PRECAUTIONS.

2.Set the selector switch to the appropriate BAT range.

3.Insert the BLACK test lead into the ( ) negative jack, and the RED test lead into the ( ) positive jack.

4.Touch and hold the RED test lead to the ( ) positive bat tery terminal and the BLACK test lead to the ( ) negative battery terminal.

5. Read the BAT scale to			determine the	battery	condition.
If the reading is in the red			REPLACE	zone, the battery
should be replaced. If the reading is in the green					GOOD
zone, the battery has considerable life				left. If the reading
is in the	?	zone, the	battery should be replaced soon
because	the	remaining power is very		low.

MAINTENANCE

GENERAL

1.No periodic maintenance is required other than replace ment of the battery, fuse, and visual inspection of the tester.

2.Keep the instrument clean and dry. Do not use solvent

for cleaning; use a damp cloth.

3. The only field replaceable parts are the 1.5V		AA cell
battery and the Fast	Acting 5mm X 20mm, 0.315A, 250V
fuse.
BATTERY REPLACEMENT
Important: A 1.5V	AA cell battery must	be installed
before using the CP7848.

1. Rotate the function range switch to the OFF position.

2.Remove red and black test leads from the test lead jacks.

3.Remove screw from rear of tester, and lift off the back cover.

4.	Install a new 1.5V	AA cell battery. Observe the polarity
	marks as indicated on the bottom of the battery com
	partment.
5.	Carefully replace	the back cover and tighten the screw.

Be careful not to over tighten the screw, because the threads in the case may become stripped.

FUSE REPLACEMENT

Important: If the tester won t work at all, check the fuse located inside the tester. If the fuse is blown, all tester func tions fail to work.

1. Rotate the function range switch to the OFF position.

2.Remove red and black test leads from the test lead jacks.

3.Remove screw from rear of tester, and lift off the back cover.

4.Replace blown fuse with a new Fast Acting 5mm X 20mm, 0.315A, 250V fuse.

5. Carefully replace the back cover and tighten the screw. Be careful not to over tighten the screw, because the threads in the case may become stripped.

0002-012-2172