ABB RELION RET670, Commissioning Manual, Page: 36 / 328

Do not touch circuitry during operation. Potentially lethal voltages and
currents are present.
Always use suitable isolated test pins when measuring signals in open
circuitry. Potentially lethal voltages and currents are present.
Never connect or disconnect a wire and/or a connector to or from a IED
during normal operation. Hazardous voltages and currents are present that
may be lethal. Operation may be disrupted and IED and measuring
circuitry may be damaged.
Dangerous voltages can occur on the connectors, even though the
auxiliary voltage has been disconnected.
Always connect the IED to protective ground, regardless of the operating
conditions. This also applies to special occasions such as bench testing,
demonstrations and off-site configuration. This is class 1 equipment that
shall be grounded.
Never disconnect the secondary connection of current transformer circuit
without short-circuiting the transformer’s secondary winding. Operating
a current transformer with the secondary winding open will cause a
massive potential build-up that may damage the transformer and may
cause injuries to humans.
Never remove any screw from a powered IED or from a IED connected to
powered circuitry. Potentially lethal voltages and currents are present.
Take adequate measures to protect the eyes. Never look into the laser
beam.
Section 2
1MRK 504 165-UUS -
Safety information
30 Transformer protection RET670 2.2 ANSI
Commissioning manual