Thomas & Betts 20D, 15D owner manual AMP-HOUR Consumption Formulas, Typical Power Consumptlon

BATTERIES

To achieve 50% cycling you should calculate your Amp-hour consumption between charging cycles and use a battery bank with twice that capacity**. Each AC appliance or tool has a rating plate on it and will be rated in either AC Amps or Watts or AC VA (Volt-Amps) apparent power. To calculate Amp- hour consumption, use one of the formulas to the right to calculate the DC Amp-hour draw for a 12 volt system.

Calculate the Amp-hours for every AC appliance or tool that will be operated on the inverter. This will provide the total number of Amp-hours used between recharges. Size the battery bank using this number as a guideline. A good rule to follow is to size the battery bank a minimum of 2 times larger than the

total Amp-hour load requirement. Plan on recharging when 50% discharged.

AMP-HOUR CONSUMPTION FORMULAS

(AC Amps x 10) x 1.1 x hours of operation = DC Amp-hours

(Watts/ DC Voltage) x 1.1 x hours of operation = DC Amp-hours

(AC VA/ DC Voltage) x 1.1 x hours of operation = DC Amp-hours

DC Voltage is 12, 24 or 32 depending on

your system.

In all formulas, 1.1 is the correction factor for

inverter efficiency.

Typical Power Consumptlon

The chart identifies typical power consumption for common AC loads. Use it as a guide when identifying your power requirements.

**Batteries are typically charged to 85% of full charge when charging with alternators without 3-stage regulators.

Typical Power Consumption

	Typical			Appliance Run Times / Amp Hours
Appliance
	Wattage
		5 Min.	15 Min.	30 Min.	1 Hr.	2 Hr.	3 Hr.	8 Hr.	24 Hr.
13" Color TV	50	.33	1	2	4	8	12	32	96
19" Color TV	100	.66	2	4	8	16	24	64	192
VCR	50	.33	1	2	4	8	12	32	96
Lamp	100	.66	2	4	8	16	24	64	192
Blender	300	2	6	12
Laptop Computer	50	.33	1	2	4	8
Curling Iron	50	.33	1	2
3/8 Power Drill	500	3.3	10	20
Icemaker*	200			2.6	5.2	10.4	15.6	41.6	83.2
Coffee Maker	1000	6.6	20	40	80	160
3 cu' Refrigerator*	150			2	4	8	12	32	96
20 cu' Refrigerator*	750			21	42	84	126	336	672
Compact Microwave	750	5	15	30	60	120	180
Full Size Microwave	1500	10	30	60	120	240	360
Vacuum	1100	7.3	22	44	88	176	264

Number in each box represents the total Amp hours used (@ 12 volt DC) based on various continuous run times.

*Note refrigeration is typically calculated using a 1/3-duty cyle.

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Many electric motors have momentary starting require- ments well above their opera- tional rating. Start up watts are listed where appropriate. Individual styles and brands of appliances may vary.

If using the same battery bank for the inverter and other DC loads, be sure to consider the power consumption of the DC loads when sizing the battery bank.

NOTE Certain laser printers, breadmakers, digital clocks and appliance/tool chargers may not operate on modified sine wave.

Part No. 90-0123-00 Libertycombi.p65 10/26/98