Tesla Powerwall 2 Installation Manual page 56

1. Follow manufacturer instructions to calibrate and zero the impedance tester before taking
measurements.
2. If the site has a 3-phase electrical system, complete the test on L1 first, then move to L2 and L3 in
sequence.
3. Follow manufacturer instructions to verify that the correct voltage is present. Switch the tester to a
voltage measurement mode and check Line-to-Neutral and Line-to-Ground voltages.
4. Follow manufacturer instructions to take an impedance measurement at the service head
Switch the tester to the appropriate impedance measurement mode and take the readings between
Line and Neutral.
5. Record the impedance measurements.
System Installation
Multiple Powerwall units can be installed side-by-side, or stacked up to three units deep with the Powerwall
Stack Kit. Stacked multi-Powerwall systems must be floor-mounted and must be anchored to an adjacent
wall. In a 9 Powerwall installation, there will be 3 groups of 3 Powerwalls each, stacked with 3 different kits.
Refer to Multi-Powerwall Installations with the Stack Kit
After the installation, measure the impedance between Line and Neutral at the terminals of Powerwall, as
shown in Figure 30 and again at the service head and compare the two measurements. In a standard
installation, the difference is within 0.1 ohm. Where a difference of greater than 0.1 ohm is measured, do
either of the following:
•
Increase wire size on the circuits supplying the Powerwalls: This simple and effective means reduces
the impedance seen at the terminals of the Powerwall.
•
Reduce and improve electrical connections. Every connection contributes to the overall impedance
seen by the Powerwall.
Figure 30: Measurement Locations After Installing the System
System Commissioning
Plan for the commissioning process to take longer with multi-Powerwall installation. Each Powerwall can take
up to 3 minutes to complete the commissioning scan and verify process, so a 10-Powerwall system can take
up to 30 minutes during this stage of commissioning.
NOTE: During the commissioning process, do not interrupt a step, turn off the system, or unplug the
communication wiring at any time.
Figure 31 shows the Multi-Powerwall installations flowchart, from design to commissioning .
Powerwall 2 AC Installation Manual
for more information.
(Figure 29).
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