Simpson 460 4 Series - Page 56

7-6
Sympton
input terminals short-
ed, and at 1000
counts when using a
stable and low im-
pedance input.
. Indication is OK on
battery. However, on
AC operation, the
reading fluctuates
and/or drifts at 0,
with the input short-
ed, and/or at 1000
counts using a stable
and low impedance
input (460-4D).
. Same as 7 above, ex-
cept indication OK
on AC but not bat-
tery operation.
Servicing Instructions
Probable Causes
measurements test set
up.
AC power source is
low or fluctuating (in-
cluding transients).
a. Battery voltage low.
b. One or more cells
defective, not in-
stalled correctly.
Cure
unwanted signals due
to ground loops, poor
connections and ca-
pacitive: and/or induc-
tive coupling. Operate
Instrument (460-40)
on battery for com-
plete isolation from
the powerline.
NOTE: If the drift
and/or fluctuation is
coming from the de-
vice being measured,
no cure is required,
the measurement is
valid, and the device
must be corrected.
Correct the power
source or use Instru-
ment on battery.
‚а. Check battery con-
dition. Refer to
para. 4.3.2. If not
OK charge battery,
refer to para. 7.3.
b. Remove cover and
check that cells are
installed correctly
and making good
contact. If OK, re-
place all cells tem-
porarily with con-
ventional “D” size
` "U. Kv