© 2021 by XOLTA
11
The XOLTA outdoor BESS is also built with a special closed metal housing designed to prevent
fire propagation between battery modules in the extremely unlikely event of battery thermal runaway.
The cabinet is made of vandal resistant steel.
Finally, every Outdoor BESS can be equipped with an external emergency stop button which
disconnects the battery racks from the grid. The emergency stop button should be installed by an
electrician when connecting the BESS to the grid
.
2.3.2 Internal electrical protection schematics of the XOLTA outdoor BESS
Figure 2.3 illustrates the protection scheme used inside the XOLTA outdoor BESS. The protection
schematics includes the following main components:
• one fast DC fuse located in each battery pack;
• two fast DC fuses located in the BPU;
• two DC relays controlled by the n-BMS (2 relays per BPU);
• one 1.5A AC relay for protection of the BPU power supply;
All metallic parts of the battery rack, battery packs and BPU are grounded.
In addition, all battery converters (PCS) provided as a part of the XOLTA outdoor BESS are grounded
and protected with AC fuses and DC and AC relays to ensure safe operation of the PCS.
Figure 2.3:
Illustration of
electrical protection
schematics used
for the XOLTA
outdoor BESS
F
200A
200A
200A
200A
200A
200A
200A
P+N+PE
3P+PE
P+N+PE
3P+PE
P+N+PE
3P+PE
200A
200A
200A
200A
200A
200A
200A
200A
BPU
BPU
BPU
PCS
30kVA
PCS
30kVA
PCS
30kVA
200A
200A
200A
200A
200A
200A
200A
200A
200A
200A
200A
200A
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
R
R
F
F
R
R
F
F
R
R
Rack 1
Rack 2
Rack N
