21150/175kw Modular PDU Installation
Recommended conductor sizes
Note: All wiring must comply with all applicable national and or local electrical codes.
Conductor sizing in this manual is based on Table 310-16 of the 2011 National Electrical Code (NEC)
with the following assertions:
• 90°C conductors (THHN) for 75°C termination
• 3 Current Carrying Conductors for Unit Input Circuit Breaker and 4 Current Carrying Conductors
for Subfeed Circuit Breaker
• An ambient temperature of 30°C
• Two conduits for each subfeed
• One Equipment Grounding Conductor for each conduit
If the ambient room temperature is greater than 30°C, larger conductors are to be selected in accordance
with the correction factors of the NEC.
Equipment Grounding Conductors (EGC) are sized in accordance with NEC Article 250-122 and Table
250-122.
Grounding Electrode Conductors (GEC) are sized in accordance with NEC Article 250-66 and Table
250-66.
The conductor sizes are recommendations for maximum configurations. Even if the load is less than the
maximum rating, it is wise to plan for future load increases. If the system is operated at a lower load than
its rating and it is desired to supply the system with a lower rated breaker and smaller conductors,
conductor ampacities are to be selected in accordance with the NEC. The transformer inrush must be
taken into account when sizing conductors.
Table for 40°C
ambient/4CCC
PDPM150G6F
480:208
PDPM150L6F
600:208
PDPM175G6H
480:415
Mains Input Φ
Cu only: 250kcmil
75°C conductor minimum
Cu only: 3/0 AWG
90°C conductor minimum
Cu: 350kcmil
Al: 500kcmil
75°C conductor minimum
Equipment
Grounding
Conductor (EGC)
Cu: 4 AWG Cu: 6 AWG Cu: 4 AWG
Al: 2 AWG
Grounding
Electrode
Conductor (GEC)
Cu: 2 AWG Cu: 2 AWG Cu: 2 AWG
Al: 1/0 AWG
Output Supplied with Power Distribution Modules
Subfeed Output Cu only: (2) 300kcmil Φ and
N, 3 AWG EGC, GEC not
required.
90°C conductor minimum
Cu only: (2) 300kcmil Φ and
N, 3 AWG EGC, GEC not
required.
90°C conductor minimum
Cu: (2) 2/0 AWG Φ and N, 4
AWG EGC, GEC not
required.
Al: (2) 4/0 AWG Φ and N, 2
AWG EGC, GEC not
required.
75°C conductor minimum