Johnson Controls Metasys N2 - Page 42

42
Network Communications—N2 Communications Bus
Notes:
For the surge protector's hard ground (HG), use 12 AWG stranded wire, 4.57 m (15 ft) maximum length.
Make sure wires entering surge protector's enclosure are not close to wires leaving the enclosure.
Metal Enclosure
SURGE2
Building One
2
4
6
8
10
1
3
5
7
9
Surge
Protector
Protected Unprotected
ASC
N2+
N2-
REF
REF
N2-
N2+
HRD GRD
NCM
HG
ASC
AHU/LCP/UNT/VAV - Unshielded N2 Bus
HG
Metal Enclosure
ASC
HG
Building Two
2
4
6
8
10
1
3
5
7
9
Surge
Protector
REF
N2-
N2+
ProtectedUnprotected
HG
Metal Enclosure
HG
N2 Bus
+
-
R
REF
N2-
N2+
N2 Bus N2 Bus N2 Bus
+
-
R
+
-
R
+
-
R
HG
Metal Enclosure
HG
Figure 25: Installing Surge Protector for AHU/LCP/UNT/VAV