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.
Relay Output Status Information
The RT7 has three PNP 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.
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.
