Product Manual

16
TRISTAR INSTALLATION
17
MORNINGSTAR CORPORATION
2.02.0
voltage sense input avoids the large voltage drops that can occur in the battery
power conductors. The voltage sense connection allows the controller to measure
the actual battery voltage under all conditions.
In addition, 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.
NOTE: Lighting mode uses the battery sense connection to measure the voltage of
the system array to determine day and night condition. Do not use the sense
connection to measure battery voltage in lighting mode.
The two battery voltage sense wires are connected to the TriStar at the
2-position terminal located between the pushbutton and the positive (+) terminal
lug.
See the diagram below:
+
+
–
+
––
Battery
+–
Figure 2.3 - Step 5 Battery Sense Connection
The two voltage sense wires (not provided with the controller) should be cut
to length as required to connect the battery to the voltage sense terminal.
The wire size can be from 1.0 to 0.25 mm
2
(16 to 24 AWG). It is recom-
mended to twist the wires together every few feet (twisted pair), but this is
not required. The voltage sense wires may be pulled through the conduit
with the power wires. Tighten the connector screws with 0.56 Nm
(5 in-lb) of torque.
The maximum length allowed for each battery voltage sense wire is
30 meters (98 ft).
The battery sense terminal has polarity. Be careful to connect the battery positive
(+) terminal to the voltage sense positive (+) terminal. No damage will occur if the
polarity is reversed, but many functions of the controller can be affected. If a TriStar
meter is installed, check the “TriStar Settings” to confirm the Voltage Sense and the
RTS (if installed) are both present and “seen” by the controller. The PC software can
also be used to confirm the voltage sense is working correctly.
Do not connect the voltage sense wires to the RTS terminal. This may cause
an alarm. Review the installation diagram for the correct battery voltage
sense connection.
Note that the battery voltage sense connection does not power (start-up)
the controller.
LIGHTING MODE - Special use of battery sense terminals
The sense terminals are used to measure the voltage of the system solar array to
determine day and night condition. For 12 Volt and 24 Volt systems, the array
voltage can be measured directly. Simply connect each sense wire to solar +/-
respectively.
For 48 Volt systems, the array voltage is too high to connect directly to the battery
sense terminals. A resistor divider must be used to divide the array voltage in half
as shown in figure 2.2b. Use two 10 kOhm resistors that are rated to 1 Watt or
higher.
Step 6 - System Wiring and Power-Up
To comply with the NEC, the TriStar must be installed using wiring methods
in accordance with the latest edition of the National Electric Code, NFPA 70.
Wire Size
The four large power terminals are sized for 35 - 2.5 mm
2
(2-14 AWG) wire.
The terminals are rated for copper and aluminum conductors.
Good system design generally requires large conductor wires for the solar
and battery connections that limit voltage drop losses to 3% or less. The
following table provides the maximum wire length (1-way distance / 2-wire
pair) for connecting the battery, solar array or load to the TriStar with a
maximum 3% voltage drop.
Wire Size 60 Amps 45 Amps 30 Amps 15 Amps
95 mm
2
12.86 m 17.15 m 25.72 m 51.44 m
(3/0 AWG) (42.2 ft.) (56.3 ft.) (84.4 ft.) (168.8 ft.)
70 mm
2
10.19 m 13.58 m 20.38 m 40.75 m
(2/0 AWG) (33.4 ft.) (44.6 ft.) (66.8 ft.) (133.7 ft.)
50 mm
2
8.10 m 10.80 m 16.21 m 32.41 m
(1/0 AWG) (26.6 ft.) (35.4 ft.) (53.1 ft.) (106.3 ft.)
35 mm
2
5.12 m 6.83 m 10.24 m 20.48 m
(2 AWG) (16.8 ft.) (22.4 ft.) (33.6 ft.) (67.2 ft.)
25 mm
2
3.21 m 4.27 m 6.41 m 12.82 m
(4 AWG) (10.5 ft.) (14.0 ft.) (21.0 ft.) (42.1 ft.)
16 mm2 2.02 m 2.69 m 4.04 m 8.07 m
(6 AWG) (6.6 ft.) (8.8 ft.) (13.2 ft.) (26.5 ft.)
10 mm
2
1.27 m 1.70 m 2.54 m 5.09 m
(8 AWG) (4.2 ft.) (5.6 ft.) (8.3 ft.) (16.7 ft.)
6 mm
2
1.06 m 1.60 m 3.19 m
(10 AWG) (3.5 ft.) (5.2 ft.) (10.5 ft.)
4 mm
2
1.00 m 2.01 m
(12 AWG) (3.3 ft.) (6.6 ft.)
2.5 mm
2
1.26 m
(14 AWG) (4.1 ft.)
Table 2.3-6a Maximum 1-Way Wire Distance (12 Volts)