Powering the LI-8250 Multiplexer

Three options are available to power the LI-8250: a standard, bare-leads power cable (part number 8150-706) to connect to a user-supplied DC power source, an indoor AC to DC power supply (part number 8250-772) for connecting to mains power, or an optional outdoor AC to DC power supply (part number 8250-770) for connecting to mains power.

Using the bare-leads power cord

The bare-leads power cord (part number 8150-706) is used to connect the LI-8250 Multiplexer to a DC power source supplied by the user. To make long-term measurements, you will require a dependable power supply, such as a solar power system or a deep cycle marine battery bank, that reliably meets your power requirements. See Power requirements and consumption to estimate your total system power requirements.

Note: Higher DC input voltages result in less power cable voltage and power loss. For example, nominal 24 VDC input voltage would be preferred over nominal 12 VDC input voltage.

To connect the power cable to your system, connect the red wire lead to the positive side of your power source and the black wire lead to the negative side. Then connect the power cord into the PWR IN port of the LI-8250 Multiplexer. Once connected, the LI-8250 will automatically power on.

Using the indoor AC to DC power supply

The indoor AC to DC power supply (part number 8250-772) provides power to the LI-8250 Multiplexer using mains power (100 to 240 VAC). This power supply is also used to power the 8250-01 Extension Manifold when running the purge pump with the Flask Sampling Kit (part number 8250-660). This power supply plugs into the ALT PWR IN barrel jack inside the case. Once connected, the LI-8250 Multiplexer will automatically power on.

The indoor power supply can be used to power the multiplexer, so that you can configure your system before field deployment. The lid of the case must be left open to use the indoor power supply.

Alternatively, you can route the power supply connector through the analyzer connection panel for long-term indoor use. To route the power supply connector through the analyzer connection panel, remove the metal seal from the panel (see Figure 2‑2) and connect the power supply into the ALT PWR IN barrel jack (Figure 2‑3).

Figure 2‑2. The metal seal can be removed to access the alternate power jack.
Figure 2‑3. Routing the indoor AC to DC power supply through the analyzer connection panel after removing the metal seal.

Warning: The indoor AC to DC power supply is intended for indoor use only and should not be exposed to the elements. Using the indoor power supply where it may become wet or damaged may shock the user or damage the multiplexer.

Using the optional outdoor AC to DC power supply

The outdoor AC to DC power supply (part number 8250-770) can be used to power the LI-8250 Multiplexer using mains power (100 to 240 VAC).

Before plugging the power supply into a power outlet, first connect the cord between the power supply and the LI-8250 Multiplexer. Connect one end to the power supply and the other to the PWR IN port of the multiplexer. The fittings of the power connectors are keyed. Be sure to align the key with the slot before tightening until snug. The connection will not fit if the key is not aligned.

Once the power supply is connected to the multiplexer, connect the power supply AC cord into the power supply and then plug it into an outlet. You will hear a click when the cord is connected to the power supply. If you do not hear a click, your connection may not be fully sealed.

The LI-8250 Multiplexer will automatically power on once power is connected.

Warning: To protect against electrical shock, the power supply must be connected to a grounded AC receptacle. We recommend that the mains power to the instrument be supplied by a ground-fault circuit interrupter (GFCI).