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2017 Sensata Technologies
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Installation
Stacking with Ground Fault Protection
If the PT controller’s internal Ground Fault Detection and Interruption (GFDI) feature is being
used—rather than an external GFDI device—in a multiple controller installation, the following
requirements must be met to ensure the GFDI circuit works properly.
• All PT controllers stacked together must have DIP switch 2 in the DOWN position (GFDI
enabled).
• Only one controller (preferably the master) must have the GFDI fuse installed, all other
controllers must have the fuse removed. This is so that only a single negative-ground
connection is made in the system. See Section 5.5 to remove the GFDI fuse.
Once the PT has been wired in a stacked con
fi
guration, refer to Section 4.13 for information on
the stacking operation.
High Voltage Network Wiring
All wiring within the PT controller’s wiring compartment must have insulation rated for the highest
voltage within this compartment. When wiring the network cable and stacking cables from one
controller to another (as shown in Figure 2-27), ensure the supplied yellow communication cables
with 300-volt rated insulation are used (see Section 2.10 for more information on these cables).
Networking Multiple PT controllers and Multiple Inverters together
When multiple inverters are stacked together, all the inverters charge to the Master inverter’s target
voltage; and any inverter in a stacked con
fi
guration can be networked to any stacked PT-100.
However, be aware that the inverters may have a variance in their battery voltage measurement,
and because of this, the inverter with the lowest battery voltage reading won’t reduce its current
until it reaches the target voltage. To utilize the most PV power, ensure the network cable from
the stacked PT-100’s is connected to the inverter with the lowest battery voltage reading.