27
TriStar MPPT Operator’s Manual
26
Installation
Step 7 - Battery Voltage Sense
The voltage at the battery connection on the TriStar MPPT 150V may differ slightly from the
voltage directly at the battery bank terminals due to connection and cable resistance. The
Battery
Voltage Sense
connection enables the TriStar MPPT 150V to measure the battery terminal
voltage precisely with small gauge wires that carry very little current, and thus have no voltage
drop. Both battery voltage sense wires are connected to the TriStar at the 2-position terminal
located between the push-button and the positive (+) terminal lug (see figure 2-1).
A battery voltage sense connection is not required to operate your TriStar MPPT 150V controller,
but it is recommended for best performance. If a TriStar meter will be added to the controller, the
battery voltage sense will ensure that the voltage and diagnostic displays are very accurate.
The voltage sense wires should be cut to length as required to connect the battery to the voltage
sense terminal. The wire size can range from 16 to 24 AWG (1.0 to 0.25 mm
2
). A twisted pair
cable is recommended but not required. Use UL rated 300 Volt conductors. The voltage sense
wires may be pulled through conduit with the power conductors.
Fuse the positive (+) voltage sense wire as close to the battery as possible. Size the fuse based on
wire ampacity - a 1A fuse can be used for #24 wire.
Tighten the connector screws to 5 in-lb (0.56 Nm) of torque.
The maximum length allowed for each battery voltage sense wire is 98 ft (30 m).
Be careful to connect the battery positive (+) terminal to the voltage sense positive (+) terminal.
No damage will occur if the polarity is reversed, but the controller cannot read a reversed sense
voltage. Connecting the voltage sense wires to the RTS terminal will cause an alarm.
If a TriStar meter is installed, check the “TriStar Settings” to confirm the Voltage Sense and the
RTS (if installed) are both present and detected by the controller. MSView
TM
PC software can
also be used to confirm the voltage sense is working correctly.
Step 8 - Network Connections
Network connections allow the TriStar MPPT 150V to communicate with other controller or com-
puters. A network can be as simple as one controller and one PC, or as complex as dozens of
controllers monitored via the internet. Review section 5.0 for more information about networking
and the connection(s) required for your system.
WARNING: Shock Hazard
Never route network cables in the same conduit as the power conductors
.
WARNING: Shock Hazard
Only use 300 Volt UL rated communication cable.
AVERTISSEMENT : Risque de décharge électrique
N’acheminez jamais les câbles réseau dans le même conduit que les
conducteurs d’alimentation.
AVERTISSEMENT : Risque de décharge électrique
N’utilisez qu’un câble de communication 300 V homologué UL.
Connect the appropriate network cables to the TriStar MPPT 150V at this time. Access to the
network ports is easier before the power cables are attached. The ports are located inside the
conduit wiring box on the lower circuit board as shown in figure 3-5.
RS-485
(4 position)
RS-232
(DB-9)
Ethernet
(RJ-45)
MeterBus
(RJ-11)
Figure 3-5. TriStar MPPT 150V network port locations
EIA-485 Connection
The four (4) position EIA-485 connector on the TriStar MPPT 150V must be removed to access
the terminal screws. Remove the socket connector by firmly grasping the connector body and
pulling away from the circuit board as shown in Figure 3-6.
Figure 3-6. Removing the RS-485 socket connector
