Sima Products STP-3000 - Manual (Page 7)

5.1 Battery Cables ( if cable installation kit is not included)
Safe operation of the Sima STP-3000 requires proper wires. Low resistance wiring from the battery to the Sima STP-3000 is
essential to deliver high input currents at low supply voltages. Do not undermine the maximum efficiencies from your inverter and
batteries with undersized copper wires.
It is recommended using 2 x # l AWG or 1 x 3/0 AWG copper cable (90°C insulation rating) as the minimum size for battery
connections to the Sima STP-3000. Minimize cable length to less than 10ft (3 meters) in order to maintain overall efficiency.
Lower efficiency results in shorter battery run-times.
Inverters may shut down below 10-volts if excessive voltage drops across the battery cables. See Table 5 for cable length and sizing.
Table 5: Recommended DC Cables Sizes for Permanent Installation, for voltage drop
less than 0.5Vdc total. Based on 90°C Cable.
SIMA STP-3000 Length of
each Cable
Up to …
Minimum Cable Size if
Using Single Cables
Minimum Cable Size if
Using Double Cables
10ft. (3m) No. 3/0 AWG 2 x No.1 AWG
15ft. (4.6m) 250 MCM 2 x No. 2/0 AWG
20ft. (6.1m) 400 MCM 2 x No. 3/0 AWG
CAUTION !
Use cables rated at 90°C. For cables rated below 90°C or run in conduit, refer to your local and national electrical codes.
Based on Table 310-17 of the U.S. National Electrical Code (NFPA 70), 1993, and on Table 1 of the Canadian Electrical
Code, Part 1.
Connect the supply cables to the DC terminals on the Sima STP-3000 via 5/16-inch ring terminals fixed to the cable with insulation stripped off over a
length of 1/2 inch (1.25cm) from the ends. Crimp the ring terminals properly. Equivalent cable box-lug terminals (available at electrical parts suppliers)
may also be used with the bare cable end inserted into the lug terminal. Secure the other cable ends to the battery terminal posts with lugs or
connectors to ensure low resistance connection.
Proper safe operation of the Sima STP-3000 requires solid, low resistance connection to
the DC power source.
Do NOT Tin the Cable Ends with Solder. Doing So Will Result in Poor Long-Term Connection!
CAUTION!
The Sima STP-3000 must be connected only to batteries with a nominal output voltage
of 12-volts. It will not operate from a 6-volt battery, and will be damaged if connected to a 24-volt battery.
5.2 AC Wiring Connections
Warning: If you are unfamiliar with high voltage wiring or unsure about how to connect this
inverter, it is recommended that a qualified electrician install this inverter.
2. Do not connect the Sima STP-3000 and another AC source (such as a generator or utility power) to the AC wiring at the
same time. The Sima STP-3000 will be damaged if its output is connected to AC voltage from another source. Damage can
occur even if the STP-3000 is switched off.
When installing the inverter into electrical systems with other power sources, a switching means MUST be included between
the STP-3000 and the other power source so that it disallows connection to both sources at the same time. This can be a
plug inserted into the desired AC power source (See Figures 10 on following page.)
1. Manual or automatic transfer switch may alternatively be used (See Figures 11 and 12). A transfer switch is a break before
make, double pole, double throw (DPDT) switch that switches both the hot and neutral wires of the AC distribution system
from one power source to the other. Manual and automatic transfer switches are available from marine and RV dealers.
They are commonly used to switch between a generator and AC (utility) power. Purchase an agency-approved switch that
exceeds the output ratings of both the inverter and the other source.
3. Do not connect the Sima STP-3000 to an AC branch circuit that has high-power consumption loads. The Sima STP-3000
WILL NOT operate stoves, and other electrical appliances that consume more than 2500 watts.
WARNING! Do not attempt your own AC wiring unless you have the knowledge and experience to do a safe job. Your RV or boat
dealer, or a licensed electrician can do the job for you if you do not wish to do your own wiring.
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