Appendix C: Nuvation Energy BMS: Best Practices
This appendix describes important concepts which need special attention to achieve a reliable
installation.
Grounding
It is assumed that Stack Switchgear will be attached electrically to an earth or local chassis ground
point, via its grounding provision. Similarly, it is also assumed that the Cell Interface modules will be
attached electrically to an earth or local chassis ground point, via the DIN rail grounding provision
(#8-32 ,
¼
" Hex-head drive, earth grounding screw), and the mounting brackets on Nuvation Energy
BMS component enclosures.
Voltages and signals on the Link Bus cables are chassis/earth ground referenced.
All connections to the battery stack are isolated from chassis ground. This includes:
▪
The Current Shunt and Stack Power connections on the Stack Switchgear unit’s internal Power
Interface
▪
The Battery Cells and Temperature Sensors connections on the Cell Interface
▪
The Ethernet and CAN interfaces on the Stack Switchgear unit’s internal Stack Controller
It is acceptable, as may be required in some cases, for the battery stack to be ground-referenced at
some single point. However, when the Stack Switchgear option for external 24 V DC (no internal AC
to DC converter) is selected, the power supply connected to the Stack Switchgear unit’s internal
power must be isolated from earth/chassis ground, with a working isolation voltage of at least 60 V
RMS.
Protective earthing conductors must be attached to each DIN enclosure at the designated ground
screw location on the Cell Interface modules' DIN clips. Furthermore, the DIN rail itself should be
connected to earth ground. 14 AWG wire with a jacket color appropriate for indicating it is a
protective earthing conductor must be used.
An example of this grounding scheme is shown below:
Nuvation Energy Stack Switchgear - Product Manual
Document ID: NE-PM-003
88
Rev 1.0, 2020-09-03
