Blue Sky Solar Boost 2000 - Manual (Page 12)

RV Power Products - Solar Boost 2000
11
A desirable installation would produce a total system wiring voltage drop of 0.6 volts or less, which can be
achieved using the wiring method shown in Figure 4 and wire sizes shown in Table 3. The wire lengths shown in Table
3 will provide a maximum voltage drop of 0.42 volts (4% of 14 volts), with the remainder of the 0.6 volts consumed by
connections fuse and so on. Note that lengths in Table 3 are shown for PV short circuit current values of 10 amps and
20 amps. For other values of PV short circuit current, maximum wire lengths scale inversely proportional to current,
such that half the current doubles the maximum wire length. For example, two 75W panels with I
SC
= 4.45 amps could
be wired with up to 22.8 feet of 10AWG wire ((10 ÷ (4.45 x 2) x 20.3ft).
Table 3 is meant to serve as a wire size guide which will lead to good boost performance with reasonable wire
sizes. The lengths shown in Table 3 are one way from the PV array to the battery, with the Solar Boost 2000 placed
somewhere in the middle. Larger wire sizes will improve boost performance whereas smaller wire sizes will reduce
boost performance. When considering wiring, fuse, and connection options think big and short as larger heavier
components and shorter wire lengths offer less resistance and voltage drop. If the preferred wiring described here is
not practical or possible, Solar Boost 2000 will still function properly but current boost performance may be diminished.
PREFERRED WIRING METHOD
Figure 4
The preferred wiring method shown in Figure 4 employs smaller wire sizes where necessary (roof wiring, panel
connections and fuse), and larger wire sizes where possible (long wire runs between PV array, panel and battery). Use
10AWG UV resistant cable to connect from the PV Panel(s) to the vicinity of the refrigerator vent or other connection
area, where the UV resistant 10AWG cable(s) connect to the PV conductor pair. As shown in Figure 4, short lengths of
10AWG wire should be used to connect this conductor pair to the Solar Boost 2000 terminal block. Figure 3 shows the
terminal block connections which will directly accept wire up to 10AWG. Connection to the battery is made in a manner
similar to PV wiring, except that a 30 amp fuse or circuit breaker must be installed in the positive wire near the battery.
Select a fuse holder with physically large internal components and a wire size of at least 12AWG.