Installation and Connections
WebRelay Users Manual
2.3 Relay Connections (Control a device over an IP network)
The Com, NC and NO relay contacts are internally connected directly to the terminal connector. No
internal fuse is provided. If the power source connected to the relay contacts can deliver more than rated
maximum contact current, an external fuse or circuit breaker must be used. The relay contacts are
normally wired in series with the power source for a device that will be controlled (the load).
When mechanical relays switch inductive loads such as motors, transformers, relays, etc., the current
will arc across the internal relay contacts each time the contacts open. Over time, this causes wear on
the relay contacts which can shorten their life span. When switching an inductive load, it is
recommended that relay contact protection devices are used. Note that the WebRelay does not provide
relay contact protection in order to provide the greatest versatility and because appropriate protection
differs for various loads.
The illustration below shows a simple example of using WebRelay
to control a device over an IP
network. The device to be controlled is wired in series with the relay contacts. Note that a fuse or circuit
breaker is shown to limit current overload. This configuration is used for control of a device using a web
browser or a control script/application running on a computer.
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Xytronix Research & Design, Inc.
