Installation
Needed for installation - not included:
Mounting hardware for the inverter
Tools for mounting and electrical wiring
Mounting
Step #1:
The STP-325 should be mounted on a solid flat surface capable of
handling the weight of the unit, with space around the unit for ventilation. It is very
important that the unit be secured using the proper sized mounting hardware (not
included) to keep the unit from moving around or becoming loose in emergency
situations.
Do not block fan opening!
CAUTION:
The power inverter must be mounted securely in any type of
moving vehicle. In an emergency situation, if the power inverter is not
securely mounted, it could cause bodily injury
Connection to Power Source
The STP-325 requires connection to a standard 12 volt DC power source such as
the batteries found in most cars, trucks, RVs and boats. The power source must
provide between 11 and 15 volts Dc and be able to provide sufficient current to power
the load. At full power the STP-325 will draw about 30 amps.
When the load exceeds 150 watts, use the cables with alligator clips for direct
connection to the 12 volt battery.
WARNING: When connecting cables, a spark
may occur. This is normal. To prevent explosion from the battery gasses, when
connecting jumper cables, always connect the wires to the inverter first.
To connect the STP-325 to your 12 volt battery (Figure1):
1.
Make sure both alligator clips are disconnected from the battery.
2.
Connect the red (+) wire to the positive (+) terminal on the STP-325 and the
black (-) wire to the negative (-) terminal.
3.
Connect the red (+) alligator clip to the positive (+) battery terminal and the
black (-) alligator clip to the frame or engine of the vehicle.
Figure 1
Figure 2
To connect the STP-325 using the cigarette plug adapter (Fig. 2):
The STP-325 also comes with a cigarette lighter plug for easy connection to the power
source, Use the cigarette lighter plug, only when powering loads less than 150 watts.
The tip of the plug is positive and the side contacts are negative.
1. Make sure the cigarette plug is not plugged in.
2. Attach the red (+) lead to the positive (+) terminal on the STP-325 and the black
(-) lead to the negative (–) terminal as shown in Figure 2 above.
3. Plug the cigarette plug into the cigarette socket in the car. Push firmly for a good
connection.
Once connected to the 12V power source, proceed to Testing the Power Inverter
Testing the Power Inverter
Make sure the 12 volt power source is wired properly to the power inverter. With
nothing plugged into the 115 VAC outlets, turn on the power switch of the STP-325.
If the green power light does not come on, turn the power switch off and check your
wiring and external fuse.
With the inverter turned off, plug the appliance you want to use into the 115 VAC
power outlet on the unit. Turn on the power switch of the STP-325. Turn on the
appliance. The appliance should now be operational.
Operation
Equipment Power Usage
It is important to use only products that draw less than 325 watts with the STP-325.
Use of products greater than 325 watts may either cause the protection circuitry of the
STP-325 to shut down or the fuse to blow. Repeated use of excessive power draw can
cause failure of the STP-325.
How to calculate power usage.
Most products have a power rating on them such as 45 watts. Others may be
marked with their current draw, such as .9 amps. To convert the current to watts
multiply the current by 115. Thus .9 amps x 115 = 104 watts.
Turn on the STP-325
Plug the appliance you want to use into the 115 VAC power outlet on the STP-325
(see the chart below for suitable appliances to use with the STP-325). Turn on the
power switch of the STP-325 so the green power light is illuminated. Turn on the
appliance. The appliance should now be operational.*
Typical Appliance
Current Draw
Cell phone charger
20 watts
Camcorder 23
watts
VCR 40
watts
Soldering iron
45 watts
Laptop computer
75 watts
Small stereo system
150 watts
19” TV
160 watts
Small power drill
250 watts
Battery Life Chart
Power
Usage
Approx
12 volt
current
Typical operation
time with 50 amp-
hr. car battery
Typical operation time with
100 amp-hr. car battery
100 watt
9 amps
5.5 hours
11 hours
200 watt
19 amps
2.6 hours
5.2 hours
*
Note :
Some products such as televisions draw a high surge current to start up. If
the appliance does not operate and the inverter turns off, you may need a larger
inverter. Check that the battery and the 12V wiring to the inverter is large enough to
handle the current draw. Be sure the battery is fully charged. You may need to turn the
power switch on the STP-325 ON and OFF a few times to get the appliance “started”.
Some motors and televisions may require this technique to get them operational.
Important
: The STP-325 will not operate most appliances designed to produce
heat such as hair dryers, heaters, toasters, and coffee makers. The STP-325 can draw
up to 30 amps from your car’s battery when operating. If you are using it for extended
periods of time, you will want to operate your car occasionally to maintain the charge
in your car’s battery. The STP-325 will also draw a small current - less than .25 amps -
when not operating, so it should be disconnected from your car’s battery if your vehicle
will not be used for a few days.
Lights and Alarms
Power Indicator (Green)
This light is illuminated when the inverter is turned on and is operating normally. If
this light goes out, either the 12 volt power supply is missing (possible blown fuse) or
some fault condition has occurred. These fault conditions include: output overload,
output short circuit, low input voltage and over-temperature of the unit. This can
happen if a device has a large start-up surge, if an appliance (like a drill or saw) is
stalled or if the inverter does not have a circulating supply of cool air.
Overload Fault Indicator (Red light )
The red light is illuminated when a current overload fault is detected. An overload
fault occurs when the power draw exceeds the inverter’s maximum capability
An under-voltage fault (beep)
An under voltage fault can occur when the input voltage reaches about 10.2 volts.
The STP-325 will sound a continuous alarm and shut off when the input voltage drops
to 9.6v to protect your battery from being completely discharged.
An over-temperature fault
An over temperature fault occurs when the STP-325 internal circuitry gets too hot
due to overload or improper air circulation. The STP-325 will turn off the green power
light.
Fuse Replacement
Cigarette Plug fuse (see figure 3)
If you overload the STP-325, it is possible to blow the fuse in the cigarette plug. If
this happens, unplug the cigarette plug from the power source, wait for the tip to cool
and unscrew the metal tip on the plug. Remove the tip. Remove the fuse and install a
new fuse rated at 15 amps.
Never use a fuse greater than 15 amps
. Replace the tip
and screw firmly but do not over tighten. Always determine why the fuse blew and
remedy the problem before using the STP-325 again.
Unit fuse (see figure 4)
If the fuse blows, disconnect both power leads from the battery. Remove the
protective cap by pulling straight up. Next, remove the fuse by pulling straight up.
Install a new 35 amp fuse and replace the protective cap.
Never use a fuse greater
than 35 amps
. Always determine why the fuse blew and remedy the problem before
using the STP-325 again.
Figure 3
Figure 4
Troubleshooting Guide
Problem Possible
cause Solution
Unit does not
operate.
Input voltage is below 10V
Fuse is blown.
Attach to proper power supply.
Determine cause for fuse
blowing and then replace the
fuse feeding the inverter.
Unit operates for
a short time and
turns off.
Load is trying to draw too
much current.
Be sure the load is less than the
rated watts of inverter. Remove
excessive load. Turn inverter off
and then on
Unit operates for
a while and gets
hot and shuts off.
Inverter is in thermal
shutdown mode.
Allow inverter to cool down. Turn
the inverter off and on to reset.
Low battery alarm
is on.
Input voltage is below
10.2 volts.
Make sure car engine is on.
Check condition of wiring.
Battery may be low and needs
recharged.
Television and
stereo
interference.
RF interference from
power inverter
Position the power inverter and
wiring as far as possible from
electronic equipment, antennas
and cables.
Re-orient as necessary.
115 VAC Output
voltage reads
incorrectly.
Modified sine wave output
can cause an incorrect
reading on a typical
multimeter.
Use a true RMS meter like a
Fluke 8060A or Triplett 4200 to
measure correct voltage.
Product Specifications
Max. continuous power output
325 watts
Surge (peak) power output
650 watts
Input voltage range
11 to 15 volts dc
No load current draw
<0.25 amp
Full load current draw
30 amps
Low battery alarm/shut-down
10.2/9.6 V, +/- 0.5 V
Efficiency 90%
Output
115VAC, 60Hz, modified sine wave
Weight 2
lbs.
Size
7” x 4.3” x 2.0”
