Selecting a Power Supply for FDMs

ITL does not ship power supplies with our FDMs, so you will need to choose a power supply to suit. The power supply you choose is important in maintaining the reliability and performance of the pump interfaces. We recommend you don't skimp on this aspect of your system.

If you want to buy a single standard power supply to run most FDMs, then:

One 15V DC, 1A, regulated power supply per FDM

will cover all except FDM115 (used in Asia-Pacific) and FDM170 (used in Europe).

More than one FDM

If you have more than one FDM, you can use the same power supply for both, but you must add up the current requirement. For example, to run 2 x FDM071, you will need a 15V DC, 2A, regulated power supply. Or you could use two separate 1A power supplies.

Power Supply Examples

Below are some examples of appropriate power supplies you can use, with links to the products on the Farnell website. There are many other options and places to buy such power supplies. You don't need these exact manufacturers or products, but a similar standard of supply is needed. See the checklist below for more details.

Manufacturer	Part #	Output Power	Example Link	Picture
XP Power	AED36US15	15V, 2.4A	Farnell
XP Power	AED45US15	15V, 3A	Farnell
XP Power	DNR18US15	15V, 1.2A	Farnell
Lambda	JWS50-15/A	15V, 3.5A	Farnell

Using the Wrong Supply: Warranty Coverage and Problems

If you use the wrong power supply (not enough voltage or current, or unregulated) then:

• The system may not work reliably
• Your warranty will be void
• We will not be able to support you until the power supply is replaced

In the past, it has been possible to get away with 12V supplies where 15V is required but this could change at any time depending on pump models or other factors out of our control.

Symptoms

If the FDM power supply is wrong, typical symptoms will be that all pumps on the loop don't work properly. Just because it has worked before, do not assume the power supply is OK as you may have been running with a small margin for error.

Checklist

• The power supply should be a professionally assembled unit of good quality.
• The power supply must be regulated. This means that it contains an active circuit to provide a smooth output at the specified voltage. It must not suffer from dips under load, or from variations in the mains AC power. This is especially important if there is other industry or equipment in the area.
• Avoid plug packs - also known as "wall warts" - that are a transformer built into the plug. While these work, it is very easy for them to fall out or come partially loose resulting in unreliable or broken communications in the middle of operations. They are acceptable in lab/test environments.
• For safety, the power supply should be enclosed, and if it has a metal case it should be grounded.
• Do not power the FDM from the PC power supply. The FDM will not be isolated from the PC and power surge or nearby lightning strike will be more likely to damage the PC.
• Avoid power supplies with multiple voltage selections. While these will normally work, they can easily be accidentally set to the wrong voltage.
• Test the output of the power supply under load (running a fully-connected FDM). Make sure the minimum voltage does not go below the requirement, prior to selecting it. To simulate a fully connected FDM you can setup an FDM071 Intelligent Current Loop with all pump channels shorted - this will not damage the FDM.
• Power for all parts of The Enabler system should be from a separate mains power circuit, wired directly back to the switchboard. Do not plug your PC or FDM into a circuit that is shared with heavy equipment such as pumps - this equipment can produce large surges and dips in power that prevent the system working correctly or even produce permanent damage.