Siemens 7SR157 Argus, Manual

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Chapter 1 - 7SR157 Description of Operation
© 2022 Siemens Protection Devices Limited Chapter 1 - Page 9 of 38
Section 2: Hardware Description
2.1 General
The structure of the relay is based upon the Reyrolle Compact hardware platform. The relay is supplied in a size
E4 or E6 case (where 1 x E = width of approx. 26mm). The hardware design provides commonality between
products and components across the Reyrolle Compact range of relays.
Table 2-1 Summary of 7SR157 Relay Configurations
Relay
Voltage
Inputs
Binary
Inputs
Binary
Outputs
LEDs
7SR1577 2 3 5 10
7SR1578 2 6 8 10
2.2 Case
The relays are housed in cases designed to fit directly into standard panel racks. The two case options have a
width of 104mm (E4) and 156 mm (E6), both have a height of 177 mm (4U). The required panel depth is
216.5mm, with wiring clearance a total of 242 mm. 290mm depth clearance should be allowed to accommodate
the bending radius of fibre optic data communications cables if fitted.
The complete relay assembly is withdrawable from the front of the case. Contacts in the case ensure that the
normally closed contacts remain short-circuited when the relay is removed. To withdraw the relay, remove the
plastic fascia cover by rotating the two securing pins and withdraw using the plastic handles. The relay should not
be carried using these handles. The relay should only be held by the top and bottom plates and the user should
not touch the exposed PCB’s.
Figure 2-1 Relay shown withdrawn