RT7 A/B Safety Relay

Technical Information

Inputs

The RT7 can be configured to operate in either of the following input options:

1. Single channel, 1 NO contact from +24 VDC, safety category 1.
2. Dual channel, 2 NO contacts from +24 VDC, safety category 3.
3. Dual channel 1 NO, 1 NC contact from +24 VDC, safety category 4.
4. Dual channel, 1 NO contact from 0V and 1 NO contact from +24 VDC, safety category 4.
5. Safety mats/contact strips 1 'contact' from 0V and 1 'contact' from +24 VDC, safety category 1.

When the input/inputs are activated and the test/supervised reset is complete, relays 1,2,3 and 4 are activated. Relays 1 and 2 are immediately de-energized when the inputs are deactivated in accordance with the input option selected. Relays 3 and 4 are either de-energized immediately or after the selected time delay. All the relays (1,2,3 and 4) must be de-energized before the RT7 can be reset.

Transistor Output Status Information

The RT7 has three (3) voltage free transistor outputs that can be connected to a PLC, computer or other monitoring device. These outputs give the input and output status of the relay.

Reset and Testing

The RT7 has two reset options; manual and automatic. The manual supervised reset is utilized when the RT7 is used to monitor safety devices that can be bypassed, i.e. to ensure that the outputs of the safety relay do not close just because the gate is closed.

The automatic reset should only be used if acceptable from a risk point of view. The RT7 can also test (supervise), if for example, contactors and valves, etc. are de-energized/de-activated before a restart is allowed.

Indication of Low Voltage

The 'On' LED will flash if the relay supply voltage falls below an acceptable level. This indication will also be given if a monitored safety mat/contact strip is actuated. See connection option 5.

Safety Level

The RT7 has internal dual and supervised safety functions. Power failure, internal faulty component or external interference will not present a risk to options with the highest safety level. A manual reset requires that the reset input is closed and opened before the safety relay outputs are activated. A short-circuit or a faulty reset button is consequently supervised.

When the RT7 is configured for dual channel input, both the inputs are supervised for correct sequence operation before the unit can be reset.

The input options 3 and 4 have the highest safety levels as all short-circuits and power failures are supervised. This in combination with double internal current limitation makes the relay ideal for supervision of safety mats and contact strips.

Regulations and Standards

The RT7 is designed and approved in accordance with appropriate standards. Examples of such are: EN 292-1/2, EN 60204-1, EN 954-1.

Connection Examples

For examples of how our safety relays can solve various safety problems, see the page of "Connection examples".

**Only for AC supply

Connection of Supply

DC Supply	AC Supply	DC Supply of AC Units
The RT7 DC option should be supplied with +24 V on A1 and 0 V on A2.	The RT7 AC option should be supplied with the appropriate supply voltage via connections A1 and A2. The S23/ must be connected to protective earth.	All AC-units can also be supplied by +24VDC to S53 (0VDC to S23). Note: With both DC and AC modules, if cable shielding is used this must be conected to an earth rail or an equivalent earth point.