This project utilizes a Furman MP-15Q (15-Amp) or Furman MP-20Q (20-Amp) to power off an appliance when water is detected by the Floodstop system. This project can be very useful to power off a washing machine, water recirculator, or tankless hot water heater if a leak is detected. In particular, appliances that can pump water such as a washing machine have an extra vulnerability for flooding and could potentially continue pumping water even if the water supply has been shut off by the Floodstop valve. For these type of devices, you may want to automatically power them off to ensure any motors or pumps are not contributing to the flooding condition.

Project Objective

The following diagram illustrates this project's goals.

Shopping List

• Floodstop Protection System (See a complete listing of available Floodstop products)
• Furman Power Controller (See a listing of other Furman Power Controllers)
• 12 VDC Power Supply (12VDC)
• 12 VDC SPDT or DPDT Relay
• A length of 2-conductor low-voltage wire (bell wire, alarm wire, speaker wire, etc.) (* length is based on your installation requirements)

Floodstop Models Furman Power Controllers DC Power Supplies Low-Voltage Relays

Furman MP-15Q / MP-20Q Power Controller

The Furman power controller product line is a heavy-duty inustrial power controller that can easily be controlled externally with either a dry contact closure or a low-voltage DC signal depending the the model. This makes the Furman power controller prefectly suited to work with the Floodstop contoller to add the capability of powering off an appliance when a leak is detected.

The Furman MP-15Q / MP-20Q is a commercial grade power controller that is intended for permanent installation in an electrical quad box. This power controller is the perfect option if you already have a double gang box and wish to install this device directly in the wall replacing your existing outlets. The Furman MP-15Q / MP-20Q provides 2 switched outlets that are switched ON when a signal voltage ranging between 8-15 VDC is applied to the input connection, an internal relay is activated and the two outlets are switched ON. The diagram below illustrates the input logic signal. Unlike other Furman power controllers, the Furman MP-15Q / MP-20Q does not have a built-in low voltage power source, so we will have to have a separate low voltage power supply.

Floodstop + Furman MP-15Q / MP-20Q

The Furman MP-15Q / MP-20Q is relatively simple integrate with the Floodstop's N.O. (normally-open) dry contact output using a combination of a low-voltage power supply to power the signal circuit and a relay to inverse the signaling logic from the Floodstop. The logic diagram below depicts how we will use the low-voltage signal across the Floodstop's dry contact output connection and relay to control the Furman MP-15Q / MP20-Q power controller.

Why Do We Need A Relay?

This project requires at least one SPDT (single-pole-double-thow) relay to inverse the signal logic. (Optionally you can use a DPDT (double-pole-double-throw) relay which could provide room for future expasion of other controlled devices.) The Furman MP-15Q / MP-20Q requires a constant low-voltage signal to remain powered ON. However, when the Floodstop is not signaling a leak condition, the output port is an open circuit. Including a relay in the circuit allows us to inverse the logic of the Floodstop's N.O. output and have a low-voltage signaling circuit connected to the Furman MP-15Q / MP-20Q power controller that is closed when there is no leak detected (and the relay is not latched). When a leak is detected and the Floodstop closes its output and that will cause the relay to latch and interrupt the consant low-voltage signal leading to the Furman Mp-15Q / MP-20Q and thus powering it OFF.

I really like the Functional Devices RIB (relay-in-box) relays. These are high quality, versitle, fully enclosed relays that can be used with a simple 12VDC signal. I personally use these in some HVAC projects in my home. You can use any 12VDC SPDT relay with this project, see here for more relay options.

Connect Floodstop to the Furman MP-15Q / MP-20Q

To control the Furman MP-15Q / MP-20Q with the Floodstop you will need a spearate 12VDC low-voltage power supply and SPDT relay. You may have an old power supply laying around that you can use for this project or your can purchase one of these. Just make sure the output voltage of the power supply is 12VDC.

Locate the N.O. (normally-open) output on the bottom of the Floodstop controller. This is the port we will be using to interface to the Floodstop.

A short connection wire should have been included in the Floodstop package that includes the necessary plug to connect to the Floodstop's output port. Most likely this connection "pigtail" will be too short for your final installation, so you can extend this connection wire by splicing on the end of a 2-conductor low-voltage wire that meets your project's length requirements.

Wiring Steps:

1. First, you will need to attach the negative (-) conductor from the 12VDC low-voltage power supply to both the negative (-) screw terminal on the Furman MP-15Q / MP-20Q and the negative (-) coil lead on the relay (depicted by the green lines in the wiring diagram below).

2. Next, attach the positive (+) conductor from the 12VDC low-voltage power supply to one of the pins on the Floodstop's output port (depicted by a red line in the wiring diagram below).

3. Next, attach a wire between the second pin on the Floodstop output port and the positive (+) coil lead on the relay (depicted by a blue line in the wiring diagram below). This completes the Floodstop trigginer circuit which controls the magnetic coil on the relay.

4. Next, attach the positive (+) conductor from the 12VDC low-voltage power supply to the common (COM) load lead on the relay (depicted by a red line in the wiring diagram below).

5. And finally, connect a wire between the N.C. (normally closed) load lead on the relay to the positive (+) input terminal on the Furman MP-15Q / MP-20Q (depicted by a blue line in the wiring diagram below). This completes the signaling circuit that controls the Furman power controller.

That's it, you are ready to test and install this project! The Furman MP-15Q / MP-20Q should now power off the high-voltage circuit the appliance is plugged into anytime the Floodstop senses a water leak! Please note that once the sensor is tripped, it does not automatically restore power when the Floodstop stops sensing moisture. To restore power to the appliance, the Floodstop sensor must be completely dry and you must press the OPEN button on the Floodstop controller. This will both open the water valves and signal the Furman MP-15Q / MP-20Q to restore power to the appliance.