This Article documents the queries raised by the customer with respect to the hardware documentation of QFX5130
Document clarification request from a customer.
The customer was asking for clarification based on the information found in the documentation: https://www.juniper.net/documentation/us/en/hardware/qfx5130/qfx5130.pdf
They referred to the “grounding” section — specifically page 73 — which states:
Answers:
“We recommend that you use this protective grounding terminal as the preferred method for grounding the chassis regardless of the power supply configuration. However, if additional grounding methods are available, you can also use those methods. For example, you can use the grounding wire in the AC power cord or use the grounding terminal or lug on a DC power supply.”
The wording “or” raises questions, and the customer wants to confirm the recommended practice.
[Answer]: The protective grounding terminal should be the primary method for grounding the chassis, regardless of power supply type. Other available grounding options, such as the AC power cord’s grounding wire or the DC power supply’s grounding terminal/lug, may also be used.
1) Is there a Juniper grounding kit – enclosed within the chassis there is nothing. With the rails packages?
[Ans]: Not included
2) In the Doku M5 screws stated – how long these screws may be mm
[Ans]: M5 standard didn't specific the length.
Common Lengths (L):
M5 screws are available in many standard lengths, such as:
* Short: 8mm, 10mm, 12mm, 16mm.
* Medium: 20mm, 25mm, 30mm, 35mm.
* Long: 40mm, 42mm, 50mm, 65mm.
3) The dimensioning of the mounting shoe is not described – distance of the 2 screws etc. best would be drawing with dimensions.
[Ans]: Two-hole ground lug dimensions vary but key specs are
wire gauge (AWG/kcmil), stud/bolt size (e.g., 1/4", 1/2"), and center-to-center hole spacing (e.g., 5/8", 1-3/4")
4) Which grounding cable size is recommended. mm2
[Ans]: Different countries use various grounding (earthing) systems like TN-S, TN-C-S, TT, and IT, dictated by national standards
please check the site location and recommend according to the local standard.
5) Doku for 5200 – also site grounding – 5120 also on the back is possible.
[Ans]: https://www.juniper.net/documentation/us/en/hardware/qfx5200/topics/topic-map/qfx5200-connecting-power.html
https://www.juniper.net/documentation/us/en/hardware/qfx5120/topics/topic-map/qfx5120-connect-power.html
6) C15 grounding vs chassis grounding investigation – need of both?
[Ans]: Recommended two hole grounding as primary
Grounding thru power cord is good to have as additional.
7) May a grounding with screws to a grounded guiding rail sufficient?
[Ans]: Not sufficient