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400 Amp Electrical Upgrade

  • Existing service is 100A, by overhead line, meter on the house.
  • New service is 400A, delivered at the edge of the property at a meter pedestal.
  • Meter pedestal has 2x 200A breakers, one for the house and one for the workshop.
    • Square D QDL22200
    • Best price I could find for the breakers was about $250 each, but an emergency disconnect which includes that same breaker was less than $200 each. So I bought two emergency disconnects and took the breakers out of them.
    • Square D Emergency Disconnect model Q2200MRBE with QDL22200 breaker
    • Bonus: That left me with two outdoor rated enclosures "for free".
  • Wiring from the meter pedestal to the house and workshop was run underground using direct burial cable.
  • Code requires an Emergency Disconnect where power goes into a residential structure, I used the same model that I pulled the 200A breakers from for the meter pedestal.

Workshop

  • 200A Load Center (Main Panel)
    • Square D QO Plug-On Neutral
    • Model: QO30M200PC
  • Wiring from Emergency Disconnect to Main Panel is three 2/0 AWG THHN/THWN-2 wires (Black for L1, Red L2 and White for Neutral) and one 4 AWG wire (Green for Ground).
  • Grounding via two methods:
    • A horiztonal ground rod laid in the trench, minimum depth of 30", connected with 4 AWG wire.
    • Ufer ground, basically a connection to the rebar inside of the workshop's concrete foundation. Also connected with 4 AWG wire.
  • Surge Protection Device installed in the panel

House

  • Wiring from Emergency Disconnect to GridBoss is three 2/0 AWG THHN/THWN-2 wires (Black for L1, Red L2 and White for Neutral) and one 4 AWG wire (Green for Ground)
  • EG4 GridBoss Microgrid Interconnect Device (MID), also called a "power gateway", the central connection point for the electrical systems
  • 2x EG4 FlexBoss21 Inverters, provide power from batteries and solar.
    • Wired to the GridBoss with three 4 AWG THHN/THWN-2 wires (L1, L2, N) and one 8 AWG wire for ground
  • 4x EG4 WallMount 280Ah Indoor Batteries, ~14.3 kWh for a total of 57.2 kWh
    • 48V, connected in parallel
    • Battery #2 is connected to Inverter #1
    • Battery #3 is connected to Inverter #2
    • All battery wires are 2/0 AWG, battery to inverter wiring is 2x positive (red) and 2x negative (black)
  • 200A Load Center (Main Panel)
    • Square D QO Plug-On Neutral
    • Model: QO30M200PC
    • Connected to the Backup Loads output on the GridBoss
    • Same size wires as the connection from Emergency Disconnect to GridBoss (3x 2/0, 1x 4 AWG)
  • Old 100A load center to be disconnected from existing 100A service and connected to the new 200A Main Panel
    • 100A breaker in the new Main Panel
    • Wiring is three 2 AWG THHN/THWN-2 wires (Black for L1, Red L2 and White for Neutral) and one 8 AWG wire (Green for Ground)
    • Conduit is 1-¼" Schedule 80 PVC
    • Later on the panel will be replaced with a new 100A Square D QO Plug-On Neutral with AFCI/GFCI breakers
  • Surge protection at multiple levels:
  • EVSE (Tesla) charger
    • 60A circuit connected to Smart Port #4 on the GridBoss
    • Two 6 AWG THHN/THWN-2 wires (L1, L2, no Neutral) and one 8 AWG wire (Ground)
    • Can be turned off automatically by the GridBoss based on conditions (e.g. grid is down and batteries are low)

Costs

Prices are aproximate and include tax+shipping. There are alot of smaller things (conduit, fittings, etc) that are not on this list.

Item Price Quantity Total
Square D Emergency Disconnect model Q2200MRBE $185 4 $740
Square D 200A Load Center $237 2 $474
Square D 80kA Surge Protection Device HEPD80 $139 2 $278
EG4 GridBoss MID $1,810 1 $1,810
EG4 FlexBoss21 Inverter $3,900 2 $7,800
EG4 WallMount 280Ah Indoor Battery $3,500 4 $14,000

Wire

Wire $/ft Length Total
4/0,4/0,2/0 URD $3.39 500ft $1,695
2 AWG URD $0.74 500ft $370
2/0 THHN/THWN-2 $4.00 35ft x3 $420
2 AWG THHN/THWN-2 $2.29 100ft x3 $687
4 AWG THHN/THWN-2 $1.52 75ft $114
8 AWG THHN/THWN-2 $0.64 125ft $80