Digital Ground Resistance Tester Model 4500
39
5.2.3 Recharging Built-In Battery
• Use the power cord stored inside the compartment within the cover.
• Plug the power cord into the female input jack.
• Connect the other end of the cord to a power outlet (voltage must be
the same as voltage indicated on the plate identified as “11”).
• The red light will turn on and remain lit while the battery is recharging.
Charging time is 14hrs. minimum for a discharged battery.
NOTE 1:
The battery may be charged for more than 14 hours without
damaging the instrument (internal protection).
NOTE 2:
Do not allow the battery to remain discharged for more than
several days.
NOTE 3:
If an instrument is not used frequently, the battery should be
recharged regularly, three-month intervals are recommended.
5.2.4 Power Supply from External Battery
The external battery should be directly connected to the appropriate
terminals. Be sure to observe the proper polarities. The external battery
does not charge the internal battery.
NOTE:
It is not necessary to remove the battery supplied with the instru-
ment when using an external battery or supply.
5.2.5 Replacing Battery
• Use the hex key to unscrew the six fastening screws from the chas
-
sis, which are located on the bottom of the case.
• Pull out the chassis
(Figure 22). Remember
to unplug the ribbon
cable which connects
the power supply board
in the bottom of the case
to the boards mounted
in the chassis.
• Remove the wing nuts,
the spacers, and the
protective cover to gain
access to the two 12V
DC battery (See Figure
23).
Chassis
Ribbon Cable
Case
Fastening Screws
X
X
Z
Y
v
BATTERY
CHARGE
BLINKIN
G DISPLAY
AND
POINTER INDI
CATE
EXCESSIVE
- TRANSIENT NOISE
- ELECTRODE
RESISTANCE
EXTERNAL
12 V
TEST
RANGE
TEST CURRENT
DIGITAL GROUND
RESISTANCE
TESTE
R
MODEL 4500
mA
2
10
50
Ω
k
Ω
2
20
200 2
20
50/60/400
Hz_110V
!
BEEPER
INDI
CATES HIGH
GROUND VOL
TAGE
AEMC
I N
S T
R U
M E
N T
S
Figure 22
