Installation and Operating Instructions

Ample Power Models AS12-100, AS24-100, AS32-100 February 1, 2000
Figure 1. AutoSwitch Wiring Diagram

Mounting the AutoSwitch
The AutoSwitch is protected against ambient humidity, but must be mounted in a dry location free of moisture, dust, and other environmental insults. The regulator will operate in temperatures to 60$^\circ $C (140$^\circ $F).
Mount the solenoid on a vibration mount or pad to reduce the solenoid's activation "clicking" noises.

AutoSwitch Orientation
All references to parts on the AutoSwitch are given with the component side of the assembly up, and terminal blocks to the left.

Wiring Diagram
The wiring diagram above is the only way to wire the AutoSwitch. Do not wire in any other way, such as combining ground wires or battery positive wires. For safety purposes, always use fuses where shown.

Signal Names and Functions
All voltages are given for 12-volt AutoSwitches. Double the voltages given for 24-volt AutoSwitches. There are two terminal blocks on the AutoSwitch, TB1, a three-pin block and TB2, a six-pin block. See the wiring diagram for orientation ...TB2 is at the top left.

Terminal Block 1

Terminal Block 2

Determining the Mode of Operation
The AutoSwitch operates in one of four modes described below.

Solar/Charge Control Mode
This mode is used to control a charge source, Device 2, such as a solar panel. In this mode, the solenoid opens and closes at desired voltage setpoints. This mode can be used with some unregulated battery chargers, but should never be used with an alternator because alternators can not tolerate being open circuited while producing current.

Load/Continuous Cross Charge Mode
This mode is used to continuously deliver energy to Device 2 whenever the voltage on Battery 1 is within the voltage setpoints. In this mode, Device 2 can be a load, such as a water pump, or it can be a second battery. The second battery can be another house battery, or a starter battery.

Voltage Limited Cross Charge Mode
This mode is used to provide power to Device 2 whenever Battery 1 voltage is greater than a set voltage, but also less than a limiting voltage. In this mode, Device 2 is typically a starter battery where it's desired to limit the maximum applied voltage. Device 2 could also be a voltage sensitive load that could be damaged by sustained high voltages. The solenoid will disconnect if the Battery 1 voltage ever falls below 13.0 Volts.

Time Limited Cross Charge Mode
This mode is used to time limit an applied voltage to Device 2. The countdown time begins when Battery 1 voltage exceeds a set voltage. This mode is another good way to cross charge a starter battery. For example, the connect setpoint could be set for 13.8 Volts with a time limit of 20 minutes. The solenoid will reconnect when the voltage falls below the 13.8 setpoint voltage, floating the starter battery with the house. The solenoid will disconnect if the Battery 1 voltage ever falls below 13.0 Volts.

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Configuring the AutoSwitch
The AutoSwitch is configured by setting switches on the DIP switch and adjusting a potentiometer, as explained below.

DIP Switch
An 8-position DIP switch is located to the near TB2, and is used to configure the AutoSwitch.

Figure 2. DIP Switch

Setting the Mode of Operation
The mode is set using switches 1 and 2 shown in Table 1 below.

Table 1. Mode Settings


Setting the Update Rate
Switch 3 sets the rate at which changes may occur ...either 4 seconds, or 16 seconds. That is, the AutoSwitch evaluates external conditions against the setpoints every 4 or 16 seconds, depending on the position of switch 3.

Table 2. Update Rate Settings


Setting the Offset Voltage
Switches 4 thru 8 set the offset voltage. The offset voltage is either added to or subtracted from the setting on the potentiometer to derive a second setpoint, (the potentiometer is the first setpoint).

The offset voltage is different for each voltage model of the AutoSwitch as shown in Tables 3, 4, and 5 below.

Table 3. 12V Model Offset Voltage Settings


Table 4. 24V Model Offset Voltage Settings


Table 5. 32V Model Offset Voltage Settings


Setting the Potentiometer
The Potentiometer, R19, is located at the opposite end of the assembly from the terminal blocks. It is a 20-turn potentiometer which has a mechanism that allows the adjustment to be continuously turned in either direction without damaging it.

In all modes of operation, the potentiometer sets the voltage at which the solenoid will close ...the potentiometer is the close setpoint. To make adjustment easy, a testpoint is provided. The testpoint is a vertical pin to adjacent to the potentiometer. By measuring the voltage on the testpoint with a digital meter, relative to ground, the potentiometer can be set at the desired closing voltage ...without having to actually generate the closing voltage.

The voltage measured at the testpoint is not the actual voltage of the battery or device 2. To get the corresponding voltage for the Potentiometer Setting, write down the Desired Closing Voltage in the table row for your AutoSwitch Model and divide it by the Divisor.

Table 6. Solenoid Closing Voltage Potentiometer


For example, to set the potentiometer so that it represents 13.5 Volts in a 12-Volt AutoSwitch, divide 13.5 by 3.614. The result, 3.735 Volts is what the testpoint will read when the potentiometer is adjusted. If you read a voltage on the potentiometer of 3.542, then the close setpoint is 12.8 Volts, (3.542 x 3.614 = 12.8).

Setting the Solar/Charge Control Mode
For this mode, the solenoid closes at the battery 1 voltage set on the potentiometer, and opens when the voltage on the house battery exceeds the potentiometer plus the offset voltage.

Using the AutoSwitch in this mode might have a potentiometer setting of about 12.8 Volts to close, and 14.4 Volts to open. The potentiometer would be set for a testpoint voltage of 3.542, and the offset switches set to 1.55 Volts. (1.55 V + 12.8 V = 14.35 Volts).

In this mode, it takes more than battery voltage falling within the close and open setpoints. The voltage on device 2 must also be greater than battery voltage for the solenoid to close. This prevents connecting a non-producing solar panel to the battery.

When the solenoid is closed in this mode, the AutoSwitch evaluates the charge source input, (Device 2), at 15 minute intervals to verify that it is still able to charge the house battery. Since the solenoid is closed, both sides have equal voltage ...the AutoSwitch opens the solenoid momentarily, measures the voltage of both sides, and only closes again if the voltage on Device 2 is greater than on the battery side of the solenoid. The AutoSwitch thus disconnects solar panels which are no longer charging, but will re-connect them whenever their voltage is higher than the battery voltage.

Setting the Load/Continuous Cross Charge Mode
In this mode, the potentiometer is the close setpoint, but the offset is subtracted from the potentiometer to derive the open setpoint. For example, using this mode to power a load, the close setpoint could be 12.5 Volts with the open setpoint at say 11 Volts. Used in this manner, the solenoid would close if battery voltage were over 12.5 and would stay closed until battery voltage fell to 11 Volts.

Using this mode to charge a second battery, the close setpoint might be 13.5 Volts with the open setpoint equal to 13 Volts. Here the solenoid would combine the batteries at 13.5 Volts and would maintain that connection until the voltage fell below 13 Volts.

Setting the Voltage Limited Cross Charge Mode
This mode is used to provide power to Device 2 whenever Battery 1 voltage is greater than the close setpoint (potentiometer) but less than the voltage limit, which is the potentiometer setting plus the offset. By adjusting the close setpoint slightly higher than the float voltage of a multi-step regulator or charger, this mode can be used to limit the absorption charge, but reconnect when the regulator or charger switches to float. For instance, if the regulator is adjusted to float at 13.5 Volts, set the potentiometer to close at 13.8 Volts. Use an offset so that the AutoSwitch will open before the final absorption voltage on the regulator is achieved. When the regulator drops back below the close setpoint, the AutoSwitch will close again, floating the starter battery along with the house bank. The solenoid will disconnect if the Battery 1 voltage ever falls below 13.0 Volts.

Setting the Time Limited Cross Charge Mode
The close setpoint is made by potentiometer. Once Battery 1 voltage climbs above the close setpoint, the solenoid is closed and the countdown time begins. The solenoid will disconnect if the Battery 1 voltage ever falls below 13.0 Volts.

Time is set using the offset switches as shown in Table 7 below.

Table 7. Time Setting


Temperature Compensation
When the AutoSwitch is configured as a cross charger, temperature compensation is applied to all battery voltage measurements and setpoints which exceed 13 Volts.

When the AutoSwitch is first turned on, the Red LED will glow until the AutoSwitch has been able to successfully open the solenoid. This may take some time depending on the mode.

The AutoSwitch must initially open the solenoid to be able to detect the state of the contacts.

If the AutoSwitch is configured as a cross charger, and the two batteries are nearly identical in voltage, the AutoSwitch will stay in its initialization mode until the two voltages differ by the amount specified in the third Offset Voltage row of Tables 3, 4, and 5. In this mode it periodically attempts to open the solenoid. That is, change the state of the solenoid and check again for the voltage difference. The Red LED will be continuously illuminated.

Operational Indications
Once the AutoSwitch is able to detect open contacts, the Red LED extinguishes and the Green LED begins to report status. The Red LED will flash error codes if detected later.

Status Indicator
The Green LED shows the status of the solenoid. Status is shown by flashing the Green LED with On and Off time in seconds as shown below.

Table 8 - Green Status LED


As shown, the Green LED merely shows the state of the contacts, and whether the state is the result of automatic operation or manual override.

Error Indicator
Abnormal conditions are reported with the Red LED. Errors are identified by On and Off times of the Red LED as shown below. If the Red LED is continuously illuminated, refer to the section on initialization.

Table 9 - Red Error LED


B1 Volts disconnected indicates that the signal on TB2-5 is missing. Over temperature error occurs at 130$^\circ $ F, (54$^\circ $ C). A temperature sensor is declared faulty if readings obtained are abnormal. This error can also be exhibited if the temperature sensor is wired in reverse.

Low voltage is indicated at 10/20/27 Volts for the 12/24/32 Volt models. Below these voltages, operation of the AutoSwitch may become erratic.

The Both Open/Close error is presented if both the open and close manual inputs are asserted simultaneously.

Most problems with new installation are due to wiring faults. Look at the signal list above and make sure that all required wires are in place and properly connected.

Remove the T+ connection to prevent a faulty temperature sensor from affecting the system.

If all required wires are proper, as verified by a multimeter on the AutoSwitch connections, call your dealer or local installer with voltage readings for all the terminal block pins, and the activity of the LEDs.

Factory Troubleshooting Support
If your dealer or installer is unable to assist you, call the Ample Power service line at 206-789-4743. Additional information may be found on the Internet at

Ample Power products are manufactured by Ample Technology, 2442 NW Market St., #43, Seattle, WA 98107 - USA

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