Agilent Technologies L4400 manual Electrical Operating Conditions, Transients, High Energy Sources

Introduction to the L4400 Series LXI Instruments 1

NOTE	Pollution Degree 1: No pollution or only dry, non-conductive pollution
	occurs. The pollution has no influence (on insulation) (IEC 61010-1
	2nd Edition).

NOTE	Pollution Degree 2: Normally only non-conductive pollution occurs.
	Occasionally, a temporary conductivity (leakage current between
	isolated conductors) caused by condensation can be expected (IEC
	61010-1 2nd Edition).

Electrical Operating Conditions

WARNING	To avoid electric shock, turn off the L4400 instrument and
	disconnect or de-energize all field wiring to the instrument and to
	the analog bus connector (if present) before removing any
	terminal block covers.

Transients

The L4421A, L4433A, and L4437A modules are designed to safely withstand occasional transient overvoltages up to 1000 Vpeak. Typically, these transient overvoltages result from switching inductive loads or from nearby lightning strikes. The lightning- caused transient overvoltages that may occasionally occur on mains power outlets may be as high as 2500 Vpeak.

The L4445A, L4450A, L4451A, and L4452A modules are intended for only low- voltage applications, and should not be connected to circuits that may generate or conduct large transient voltages.

High Energy Sources

These instruments are designed to handle inputs up to their rated currents or their rated powers, whichever is less. Under certain fault conditions, high energy sources could provide substantially more current or power than a module can handle. It is important to provide external current limiting, such as fuses, if the instrument inputs are connected to high- energy sources.

CAUTION	Install current limiting devices between high energy sources and
	the module inputs.

L4400 User’s Guide 3