Hirsch Installation and Wiring Best Practices

Enclosure Mounting

Avoid mounting near sources of Electromagnetic Interference (EMI).

Examples include:

• Power lines

• Transformers

• Induction Heaters

• Electric Motors

• Electrostatic Discharge (ESD)

Enclosure Wiring

• Only use provided knockouts when feeding wires and cables into the enclosure. Any added holes in the enclosure may allow unwanted electromagnetic interference to enter the enclosure and cause unpredictable issues.

• Use appropriate cable clamp connectors or metal conduit at all knockouts. This will help secure and protect wiring. 

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• If metal conduit is being used, ensure the conduit is grounded to earth ground.

• Splicing of wires and conductors is discouraged and should be avoided.

• Spare conductors in cables should not be eliminated. Cut the spare conductors to the same length as the conductors in use and wrap them around the cable jacket for possible future use.

• Cable jackets and shields should never be stripped back farther than necessary to make connection to the system board.

Cable Management

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• Avoid running cables on top of or underneath the controller printed circuit board.

• Plastic tie wraps are useful in keeping cables organized. When using tie wraps, do not over-tighten. 

• Avoid bundling the Ethernet data cables with other cables. 

Shielded Cable Basics

Why shielded Cable is Important

Typically, locations such as equipment closets and factory floors are electrically noisy environments. Electrical noise, either radiated or conducted as Electromagnetic Interference (EMI), can disrupt the operation of other electrical equipment. Shielded cable is good protection against the effects of EMI.

Cables can act as either a source or receiver of EMI. As a source, the cable can either conduct noise or act as an antenna to radiate EMI. As a receiver, the cable can pick up EMI that is radiated from other sources. A shield works to reduce EMI in both of these cases.

Shielded cable is a primary way to combat EMI. The shield surrounds the inner signal and power conductors. The shield can both reflect external energy and also conduct it to ground.

Types of Shielded Cable

Cables come with various degrees of shielding and effectiveness. The amount of shielding is dependent on the environment the cable that is being used. 

Levels of protection offered by shielded cable:

Guidelines for Effective Shielding

• Make sure to use a cable with sufficient shielding for the applications environment. In moderately noisy environments, a foil alone may be sufficient. In noisier environments, braided or foil-braided cable may be necessary.

• Make sure the equipment the cable is grounded to is connected to a proper ground. Use an earth ground whenever possible and check the connection between the ground point and the equipment. Noise can only be reduced by a low impedance path to ground.

• Ground the cable at only one end, typically the controller side. Connecting at both ends can create unwanted ground loops.

AC Power Wiring

• The AC power wiring to the DC power supply consist of the AC LINE (L), AC NEUTRAL (N), and SAFETY GROUND (G). These AC lines connected to the panel must NOT be interchanged.

• Interchanging AC LINE and NEUTRAL could expose the DC power supply to the hot side of the AC supply even when the AC LINE has been switched off.

• Interchanging the AC LINE and SAFETY GROUND could energize the case and cause a lethal shock.

• Interchanging the AC NEUTRAL and SAFETY GROUND could cause ground currents to flow through unintended ground paths, causing unpredictable/improper system operation.

Supervised Alarm Input Wiring

• Alarm Input wiring can be sensitive to electromagnetic interference so it is recommended to use a high quality shielded cable.

• Strip only enough of the cable jacket and shielding to allow for proper wiring of the connector.

• The shield foil/braid should be stripped to the same length as the cable jacket.

• The shield wire should be stripped to the same length as the signal conductors.

• The shield wire should be terminated at the controller using the dedicated shield connection of the supervised alarm connector. The other end of the cable shield should be left unconnected.

• Ensure exposed shield wire does not come into contact with any other shield wires, the metal enclosure, or any other metallic surfaces. 

• Shrink tubing can be used on exposed shield wire to ensure unwanted contact with metal surfaces.

Relay Wiring

• It is not critical to use shielded cable when connecting relays to door strikes.

• Strip only enough of the cable jacket to allow for proper wiring of the connector.

Reader Wiring

Wiegand Wiring

• Wiegand Reader wiring can be sensitive to electromagnetic interference so it is recommended to use a good quality shielded cable.

• Strip only enough of the cable jacket and shielding to allow for proper wiring of the connector.

• The shield foil/braid should be stripped to the same length as the cable jacket.

• The shield wire should be stripped to the same length as the signal conductors.

• It is recommended to only terminate the shield at the panel and not at the reader.

• The shield wire should be terminated along with the reader ground at the provided ground terminal of the  Reader connector.

• If the Wiegand reader has an available drain connection, connect the drain line to the cable shield otherwise only connect the cable shield at the controller.

• Ensure exposed shield wire does not come into contact with any other shield wires, the metal enclosure, or any other metallic surfaces. 

• Shrink tubing can be used on exposed shield wire to ensure unwanted contact with metal surfaces.

RS-485/OSDP Wiring

• RS-485/OSDP Reader wiring can be sensitive to electromagnetic interference so it is recommended to use a good quality shielded cable.

• Strip only enough of the cable jacket and shielding to allow for proper wiring of the connector.

• The shield foil/braid should be stripped to the same length as the cable jacket.

• The shield wire should be stripped to the same length as the signal conductors.

• It is recommended to only terminate the shield at the panel and not at the reader.

• The shield wire can be terminated along with the reader ground in the provided location of the RS-485/OSDP Reader connector.

• Another option to terminate shield wire would be to terminate the shield wire at an unused MATCH shield terminal as shown above. Ensure the exposed shield wire is covered with shrink tubing.

• Ensure exposed shield wire does not come into contact with any other shield wires, the metal enclosure, or any other metallic surfaces. 

• Shrink tubing can be used on exposed shield wire to ensure unwanted contact with metal surfaces.

Scramblepad Wiring

• Scramblepad wiring can be sensitive to electromagnetic interference so it is recommended to use a good quality shielded cable.

• Strip only enough of the cable jacket and shielding to allow for proper wiring of the connector.

• The shield foil/braid should be stripped to the same length as the cable jacket.

• The shield wire should be stripped to the same length as the signal conductors.

• It is recommended to only terminate the shield at the panel and not at the reader.

• The shield wire should be terminated at the controller using the dedicated shield connection of the Scramblepad connector. The Scramblepad side of the cable shield should be left unconnected.

• Ensure exposed shield wire does not come into contact with any other shield wires, the metal enclosure, or any other metallic surfaces. 

• Shrink tubing can be used on exposed shield wire to ensure unwanted contact with metal surfaces.