SQID: Chassis Connection

The SQID must be effectively bonded to the machine’s chassis to ensure reliable operation of the unit in the presence of electromagnetic interference. To ensure that a high level of hardware quality is maintained, the SQID has a number of features, which provide both flexibility and stability.

A 6.35mm Fast-On is located on the left hand edge of the board (component reference E700). Attach a short bonding strap to this connector.

If the unit is housed in a Phoenix Contact plastic extrusion (Phoenix PN: 29 51 02 0/x) then an earthing end-plate may be used (Phoenix PN: 29 59 46 3) in conjunction with a hole (H701) located by the IN port.

When using a DIN rail, the preferred method for grounding is to connect the end-plate to H701 via a screw. Then connect DIN rail to the chassis. Otherwise a fast-on E700 should be used with a short length of cable.

If you are mounting straight to a chassis then ground H701, H706, and H703.

If the unit is mounted on pillars then H706 and H703 are available for connection to a bonding pillar.

Thick tracks from the chassis connection points also run to J400 where they are called EARTHGND and EARTHGND2.