22
Wattmeters
1.
GENERAL INSTRUCTIONS
Thank you for purchasing this
PX 110
or
PX 120 wattmeter
.
This instrument complies with the NF EN 61010 safety standard concerning electronic
measurement instruments. For your own safety and to prevent damage to the instrument, it
is essential to respect the instructions given in this manual. The contents of this manual must
not be reproduced in any form without our consent.
1.1
Precautions and safety measures
1.1.1
Before using
* This instrument can be used for testing category-III installations, with voltages which
never exceed 600 V (AC or DC) in relation to the earth.
* Definition of installation categories (see publication IEC 664-1):
CAT I:
Category I circuits are circuits protected by low level transient over-voltage
limiters
Example: protected electronic circuits
CAT
II
: CAT
II
circuits are household appliance or similar power circuits, which may
carry medium-level transient over-voltages.
Example: household appliance and portable tool power supplies
CAT III : CAT III circuits are high-power appliance power circuits, which may carry
high-level transient over-voltages.
Example: industrial machinery or instrument power supplies
CAT IV : CAT IV circuits are circuits which can carry very substantial transient over-
voltages.
Example: power feeder
* To use this instrument, the user must comply with the usual safety rules in order to:
- ensure protection against electric currents,
- protect the instrument against incorrect operations.
* For your safety, only use the leads and the fuse delivered with the instrument: they
comply with the norm EN 61010-1. Before using, always check that they are in
perfect working order.
1.1.2
When using the instrument
* Never exceed the protection limit values indicated in the specifications for each type
of measurement.
* When the instrument is connected to the measurement circuits, do not touch any
unused terminals.
* When repairing TVs or measuring on power switching circuits, there may be high-
amplitude voltage surges on the measuring points which can damage the instrument.
These surges can be attenuated by using a filtering probe.
Chapter I
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