PVI 36TL Installation and Operation Manual (Rev H)
DOCR-070588-H
Page
51
of
120
Warning:
Risk of Electric Shock.
Make sure all DC and AC power to the unit has been disconnected before opening
the inverter wiring box and make sure hazardous high voltage and energy
inside the equipment has been discharged.
The SolrenView data logger acts as the Modbus Master and can support up to 32
inverters on the Modbus (RS-485) daisy chain utilizing Modbus IDs 1 through 32. If more
than 32 inverters are required, additional SolrenView data loggers must be added, with
each logger supporting up to 32 inverters per daisy chain.
Solectria recommends that the Modbus (RS-485) daisy chain for PVI 36TL inverters is
limited to a maximum of 1600 ft. (500m).
The inverter Modbus (RS-485) connections must utilize a Shielded Twisted Pair Modbus
cable such as Belden 9841 or Southwire 58165802.
The cable shield continuity should be maintained for the entire length of the daisy chain
and should only be connected to Chassis GND inside the first inverter in the daisy chain
as shown in figure 2.38. The shield should not be connected to any of the other inverters
to prevent any possible ground loops.
Star or T Modbus (RS-485) network topologies should be avoided. See Figure 2.34.
It is important to terminate the Modbus (RS-485) bus daisy chain correctly at both ends
with 120 ohm resistor to minimize any bus noise and signal reflections. The bus should
have termination resistors turned on at the SolrenView data logger and at the last
Modbus device in the daisy chain, typically an inverter. It is important that the Modbus is
only terminated at the opposite ends regardless of there being only 2 or up to 32
devices connected to the bus.
The Modbus termination resistors are built into the PVI 36TL inverter which can be
turned on by flipping switch S402 to the ON position as shown in Figure 2.35. The S402
switch should always be left in the OFF position except for the last inverter in the daisy
chain.
The SolrenView data logger ships with the Modbus termination resistors turned on. For
more details see Figure 2.41
