how to wire 2 float switches in series

How do I install and wire my float switch? Where can I find a circuit diagram of a float switch? Where can I find the wiring diagram of the float switch? You asked, and today, we answer. Installing a float switch doesn’t have to be difficult, but it can be a bit confusing if you don’t have a visual aid or two. Remember that what you are wiring is a means of turning things on and off. Thinking carefully about when you want something to turn off and when it should turn on will help you visualize the wiring and apply the schematic to real world control. Simple pump control arrangement using float switches. We’ll look at single and double switch arrangements and how to wire them, and then look at equivalent circuits using Kari series float switches.These instructions and diagrams will teach you the basics of float switch control wiring. They certainly do not apply in all situations, especially where additional control equipment is needed to handle large motors. However, with a bit of groundwork, you’ll be wiring like an old pro in no time. The rising action of the float can close (i.e. turn on) a “Normally Open” circuit, or it may open (turn off) a “Normally Closed” circuit. Installation situations may include a Normally On float switch that turns on the pump to fill the tank (Control Diagram 2) or a Normally Closed float switch that turns off the tank filling pump (Control Diagram 1). In both diagrams, terminal 1 in the control circuit represents the landing point for the (+) wire of the float switch and terminal 2 for the (-) wire. A two-wire float switch can easily be used to turn the pump on or off. Mount or hang your switch to the desired level, thread the wires into the watertight junction box (or out of the liquid area and then into the junction box), check the connections back to the control unit and the power of the switch. This is a very simple solution, but it also has problems because the level fluctuations will cause the float to vibrate, which will cause the pump motor to turn on and off in succession. And now your simple solution ignited a pump motor. So what can we do to protect the pump motor? Wiring two floating switches We can add a second switch to create hysteresis. Hyste-what?? Yes, we will go there. Wait. What we need is a way to allow the level switch to be turned on and off without pedaling the pump motor at the same time. We could add a delay, but that doesn’t help with monitoring and responding to tank conditions; it just overrides the switch. However, if we add a second switch that resembles the first and wire a sealing relay around one of them, we get the control we’re looking for. Let’s start by looking at Control Diagram 3 with two Normally Closed switches. This circuit can be used to control a pump that fills a tank. The first switch (L) is set to the desired minimum liquid level in the tank. The second switch (H) goes at the desired maximum Read more: how to open the secondary locker When the liquid is under both switches, both are closed; the pump runs, fills the tank. When the liquid is full through the first switch, it opens. However, the sealing relay A has been activated and closed, bypassing the now open switch L (effectively “seal”), so the pump continues to run until the high level switch H open. When the high level switch is open, motor relay P opens, stops the motor and seal relay A opens, so no more liquid enters the tank from this pump. Suppose a valve downstream of the tank is opened, allowing liquid to escape from the tank. When the liquid level drops, the high level switch H closes. But since both the low level switch L and the sealing relay A are open, the pump motor cannot start, the liquid level in the tank must actually fall below the low level switch L for the motor to start. At that point, both the low and high level switches will be closed, completing the circuit and activating motor relay P to start the pump. At the same time, the sealing relay A will be activated, switching around the low level switch L. So, when the low level switch L opens when the pump is full, the sealing relay will keep the circuit closed. and the pump continues to pump. This cyclical action is called hysteresis. When the liquid level drops below the low level switch, the pump will run until both switches are open. The liquid level can fluctuate up and down, the low level switch can be opened or closed, and the pump will continue to run smoothly. Similarly, once the high level switch is open, the pump will not run until both switches are closed. Regardless of the level of vibration, the pump motor does not vibrate anymore. We’ve got level control, reasonable pump-motor life, everything we could want, right? Let’s wind up. We need to wire both float switches back to our control circuit, plus we have to add contacts and sealing relay A. Low level switch wires to terminals 1 and 2, switch high level to terminals 3 and 4, and the contacts for sealing relay A to terminals 5 and 6. So that’s at least four, if not six, wires that need to be connected to the control circuit. (Wiring the sealing relays and contacts will depend on your controller.) That’s not too bad: two float switches, an additional relay, and four to six wires. But what if I told you you could do it with just two ropes? Not two additional wires, just two wires. 2 Controlling wire pumps with Kari Float SwitchThat’s right. With the KARI series 2L float switches, you get the same delay control using one switch and two wires instead of two switches and four or six wires. You ask “What is this magic,”? Simple: each KARI series float switch has multiple micro switches and control circuits built into the float. When the KARI monoflow float rises with the liquid level in the tank, it will tilt to one side. Micro switches inside the float will activate at factory-set angles when the float tilts and the pre-programmed control circuit will respond accordingly. We can go back to control scheme 1: only need two wires between switch and motor control circuit, wire (+) to terminal 1 and (-) to terminal 2. No sealing relay, no auxiliary switch, nothing else. Two wires and you’re done. ! Instead of four wires for simple, two-level hysteresis, the KARI series 3H float switches give you two-level hysteresis and three-wire alarms. Take a look at Control Diagram 4. At the bottom, you have the wiring terminals for the switches that provide the delay (wires 1 & 2). The next line is for a high level alarm (i.e. a level higher than the high level delay switch). As with the sealing relay above, the wiring required for the alarm contact will vary depending on your control device. All that remains is to install the switch according to the manufacturer’s instructions for your desired levels. time to talk specifically about engine starting and engine control. For small motors – DC motors, motors up to 1 HP – the relay-controlled contactor shown in the diagram above may be enough to start the motor. These motors (or the load they are driving) will do no harm in starting and stopping through a contactor that acts as an on-off switch. motor starting and maintenance factors, making the contactor insufficient as a stand-alone motor starter. Such motors need integrated control and overload protection to start safely and remain protected at full load. Fortunately, most motors of this size will be controlled via a motor control center (MCC) or a dedicated control panel, both of which are fully capable of integrating control circuits. and the device is the same as what is shown above. and the motor you will control with a float switch may be large enough to require these built-in controls. While setup is more complicated than the wiring diagrams provided above, the wiring is often simplified for the end user as the system vendor has already done most of the work. how powerful or complex the system is. Everything from installing float switches to troubleshooting will become easier. And of course, we’re always here to help if you feel you need it. top photo credit: PEO ACWA via flickr cc crop