Allen-Bradley Guardmaster, User Manual

Page: 24 / 100

24 Rockwell Automation Publication 440R-UM013E-EN-P - March 2017
Chapter 3 Power, Ground, and Wire
Figure 12 - Example Connections to Safety Mats
Because the safety mats are parallel plates, they have a significant capacitive
effect. The larger the mat, the more capacitance. If the capacitance is too large,
the safety relay does not function properly. See Capacitance Effect on page 71
for further information.
Safedge Safety Edges
The Allen-Bradley Guardmaster Safedge pressure sensitive safety edges can be
connected to CI, DI, DIS, and SI safety relays. Figure 13 shows how Safedge
edges are constructed of conductive rubber with two embedded wires that run
the length the edge. Each wire forms a channel for the GSR safety relay. When
the edge is compressed, a low resistance is created between the two channels.
The Safedge edge must be constructed with four wires (two wires exit each
end). See publication 440F-UM002 for further information on the Safedge
edges.
IMPORTANT For fault detection purposes, GSR relays must be configured for monitored
manual reset when connected to Safedge safety edges.
IMPORTANT
When using safety mats, the DI and DIS safety relays must be set for AND
logic. If only one mat is used, the second input must be connected with
jumpers or to another safety device. If another safety device is connected to
the second input, the outputs of the safety device must be ON during
configuration and during powerup.
DI and DIS
Pulse
Testing
Outputs
S11 S21
Mat 1 Mat 1 Mat 2
S22
Input 2 Input 1
S12 S42 S32
CI and SI
Pulse
Testing
Outputs
S11 S21 S22
Input 1
S12
DI and DIS
Pulse
Testing
Outputs
S11 S21
Mat 1
S22
Input 2 Input 1
S12 S42 S32
EM Device
TIP
Older Allen-Bradley Guardmaster MSR relays could be tickled by tapping on
the safety mat, which generated fast cycles. This activity caused the relay to
fault because the fast cycles violated the recovery time specification. GSR
relays have a 20 ms recovery time, so this fault is not likely to occur.