![](/images/new-backgrounds/1206875/2068757x1.webp)
Operator Safety Information
The safety information in this summary is for the benefit of operating personnel. Warnings and Cautions will also be found throughout the manual where they apply.
PRODUCT USAGE WARNINGS:
For fire and electric shock protection, DO NOT connect the input channels to objects at elevated electrical potential. The common terminal of each measurement input channel is not isolated from the common terminal of the 9V DC input power connector and the RS-232 serial data port while that channel is being measured.
This interconnected common circuitry is not connected to ground or to the enclosure of the OM-550. If the OM-550 is interconnected to a desktop computer, its internal circuitry very likely could be connected to ground through the serial data port of the computer. The enclosure and the measurement circuitry provide functional isolation of the measurement and data circuitry sufficient to allow for small electrical noise-related potentials to occur. This functional isolation is not intended for electrical safety isolation. Therefore for electric-shock protection and to prevent fire and damage to data interconnect wiring due to high currents, the input channels must not be connected to objects at elevated electrical potential.
∙Do not operate the OM-550 in flammable or explosive atmospheres. Such usage constitutes a fire or explosion risk.
∙For electric-shock protection, only operate the AC power adapter indoor location.
∙For continued fire and electric shock protection, use only the specified power adapter.
∙For continued fire protection, use only the specified optional DC power cable, which incorporates a two-ampere fuse.
A two-ampere fuse is incorporated in the cigarette lighter plug which is part of the DC power cable. This fuse provides overcurrent protection should a short or overload circuit occur in the OM-550 or the DC power cable.