Sima Products STP-3000 owner manual Appendix a Battery Sizing, Troubleshooting Guide

8.2 Troubleshooting Guide

Problem and symptoms	Possible Cause	Solution
Low output voltage	Using an average reading	Use true RMS reading meter. See section 2.2
(96 to 104 V AC)	voltmeter.	of manual
Low output voltage and current	Overload.	Reduce load.
indicator in red zone.
No output voltage and	Low input voltage.	Recharge battery, check connections and cable.
voltage indicator in lower red zone
No output voltage,	1. Inverter switched off.	1. Turn inverter on.
no voltage indication.	2. No power to inverter.	2. Check wiring to inverter. Check battery fuse
	3. Internal fuse open.	3. Have qualified service technician check and replace.
	4. Reverse DC polarity.	4. Have qualified service technician check and
		replace fuse, Observe Correct Polarity.
No output voltage,	High input voltage.	Make sure that STP-3000 is connected to 12V
voltage indicator in upper red zone.		battery, check regulation of charging system.
Low battery alarm on all the time,	Poor DC wiring, poor battery	Use proper cable and make solid connections.
voltage indicator below 11V.	condition.	Change battery or use new battery.
No output voltage, OVERTEMP indicator	Thermal shutdown.	Allow the STP-3000 to cool off. Reduce load if
on, load in excess of 3000W with 250/300A		continuous operation required.
input current.
No output voltage, OVERTEMP indicator on,	Thermal shutdown.	Improve ventilation, make sure ventilation openings in
load less than 3000W with		The STP-3000 are not obstructed, reduce ambient
300A input current.		temperature.
OVERLOAD indicator on.	1. Very high power load.	1. Remove or reduce load.

Appendix A - Battery Sizing

For continuous usage, deep-cycle batteries are rated by reserve capacity in minutes or by ampere-hourcapacity. Reserve capacity measures the duration a battery delivers its rated current – normally at 25 amperes. A battery of 60 minutes reserve capacity can deliver 25 amperes for 60 minutes before completely discharged. The measure of cranking amperes used to rate starting batteries in automotive is not suitable for deep-cycle batteries. It is better to size your batteries more conservatively for unexpected variations. More reserve capacity means your batteries will not be discharged as deeply so that battery life will not be unduly shortened. It is recommended that the consumed ampere-hour loading should be kept less than 50% of the battery's rated capacity.

Ampere–hour (AH) capacity measures battery amperage being delivered for a rated duration – normally at 20 hours. A typical marine or RV battery rated for 120 ampere–hour delivers 6 amperes for 20 hours.Battery capacity varies inversely with discharge current. At 5 amperes loading, a battery of 100AH discharges for 20 hours but at 20 amperes loading, the same battery may only last for 4 hours with its capacity reduced to 80 ampere-hours. It is therefore not suitable to compare rated ampere-hour capacity directly with battery reserve capacity.Observe the following steps to determine your battery capacity requirements:

STEP 1 - Determine the wattage of each appliance to be driven by the Sima STP-3000. Multiply any current ratings by 115 to obtain the power consumption in watts.

STEP 2 - Estimate duration of tool operation between battery charge-discharge cycles or each appliance being driven by the Sima STP-3000.

STEP 3 - Calculate the total watt-hours of operations, total running time in hours, and average power consumption as exemplified below: Average Power Consumption = 3275 watt-hrs ÷ 1.8 hours = 1819.44 watts

For Sima STP-3000inverter, Ampere-Hour Consumed = 3275 ÷ 10 = 327.5 ampere-hours

STEP 4 - Locate the battery size meeting the required operating time at the calculated power consumption level from Table 3. For the example shown, operation duration of 1.8 hours at 1819.44 watts requires the smallest battery size as two 400 amp-hr batteries in parallel, offering about 10 to 12 hours of operating time.

Table 3. 12-Volt Battery Sizing Chart (for reference only)

Example for Step 3 of Battery Sizing

Equipment	Power Consumption	Operating Time	Watt Hours (Power x Operating Time)
Coffee Maker	1000 watts	0.3 hour	300
Cordless Steam Iron	1200 watts	0.5 hour	600
Vacuum Cleaner (380W)	1600 watts	0.25 hour	400
Washing Machine	2000 watts	0.25 hour	500
Window Type (12100Btu/h)	2950 watts	0.5 hour	1475

Totals

1.8 hours

3275 watt-hours

Inverter				BATTERY SIZE
output	Typical Load	AMP-HRS:	50	75	100	200	400
power		Reserve	90 minutes	140 minutes	180 minutes	400 minutes	900 minutes
(watts)		capacity
50	Stereo system		9 HOURS	14 HOURS	20 HOURS	40 HOURS	80 HOURS
100	19” colour TV		4 HOURS	6 HOURS	10 HOURS	20 HOURS	40 HOURS
200	Computer system		2 HOURS	3 HOURS	4.5 HOURS	10 HOURS	20 HOURS
300	Blender		1.3 HOURS	2.2 HOURS	3 HOURS	6 HOURS	12 HOURS
400	Power drill		1 HOUR	1.5 HOURS	2 HOURS	4.5 HOURS	10 HOURS
600	Small coffee maker				1 HOUR	2.5 HOURS	6 HOURS
800	Small microwave	Operating				1.5 HOURS	4 HOURS
1000	Automatic Toaster					1 HOUR	3 HOURS
1200	Cordless Steam Iron	time				0.5 HOUR	2 HOURS
1500	Full size microwave		N.R.	N.R.		0.5 HOUR	2 HOURS
2000	Grill Microwave				N.R	0.3 HOUR	1 HOUR
	Oven 42L(1.5Cu.ft)
2500	Hair dryer &					0.2 HOUR	0.7 HOUR
	washing machine
2950	Window Type					0.15 HOUR	0.5 HOUR
	(12100Btu/h)

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