Pool and Spa Basic Electricity

Ground Fault Circuit Interrupter (GFCI)

When equipment or wiring fails it might draw more current than the appliance can use, burning out the appliance. The circuit breaker is designed to break the circuit when demand exceeds the rating of the breaker. Thus circuit breakers are designed to protect equipment, not humans.

The GFCI is designed to protect humans. It is a circuit breaker that detects problems at a low enough level to protect you before lethal doses are delivered. it breaks a circuit when it detects a ground fault. . The GFCI constantly measures the current going out of the appliance and coming back into it. If by chance any grounding takes place, such as if the metal case of an appliance were electrified, and you touch it, completing a pathway for current to the ground, the GFCI detects the drop in the current it is receiving and breaks the circuit. The GFCI detects variations as low as 0.005 amp, . The GFCI cuts the circuit within one-fortieth of one second, so it is not only sensitive, it's quick.

There are three basic styles of GFCI that you will likely encounter in pool and spa work. The first looks like a standard circuit breaker in the electrical panel, with a test button in the face of the breaker in addition to the on/off breaker switch. By pressing the test button, you simulate an unbalanced current condition inside the breaker and thereby testing the efficiency of the GFCI. The GFCI breaker resets the same way a normal panel breaker does.

The second type of GFCI is built into a wall outlet, containing a test button and a switch to reset the GFCI as you might install for plugging in a portable spa.

The third type is a portable GFCI, a unit that plugs into a wall outlet. The appliance is then plugged into the GFCI, making the outlet a GFCI outlet.

All types of GFCIs, like any other mechanical device, are subject to failure and should be tested from time to time.

Though GFCI provide so much safety, why aren't all breakers and outlets GFCIs? The first answer is probably cost, for they cost two to four times as much as a standard one. Practical reason is that some appliances or circuits operate normally with slight variations in current, so the GFCI would constantly be breaking circuits for the wrong reason. In fact, slight variations might occur in the pool or spa equipment, causing the GFCI to trip even though everything is functioning properly. For this reason, it is best to locate the GFCI as close to the appliances as possible.

If a GFCI keeps breaking the circuit, you troubleshoot the problem in the same manner as any other breaker. As described earlier, start by disconnecting the appliance and resetting the breaker, check the wiring, disconnect the load at the breaker. If you have a GFCI serving a skid pack, the problem can exist in any single piece of equipment, so these must be disconnected one at a time and the GFCI reset after each to detect the appliance with the problem. Start with the light, then proceed to the blower, electric heater, pump motor, control devices for, the problem might exist in the control panel.

The National Electric Code (NEC) specifies that electrical outlets located within 15 feet of the water's edge must be protected by a GFCI and that circuits for all underwater lighting be so equipped. Underwriter's Laboratory (UL) requires all portable spas be wired with a GFCI.

Switches

To control the operation of each appliance circuits are interrupted at some point by switches A breaker should never be used as the on/off switch for an appliance because repeated switching will weaken the breaker.

Air switches, time clocks, and other control devices all these are switches, turning appliances on or off by completing or breaking an electrical circuit. An understanding of the basic concept of switches will help you troubleshoot electrical problems.

A basic switch, which is a break in the hot line of a circuit. This is the most basic on/off switch, called a single pole, single throw (SPST) switch. This switch handles one circuit (single pole) each time the switch is thrown. The SPDT second drawing depicts a single pole, double throw (SPDT) switch. In this case, there is still only one circuit of electric current, but when this switch is thrown one direction, it electrifies one appliance, and when it is thrown the other way, it electrifies another appliance. Depending on the appliance(s), you might use several variations of poles (circuits) and throws (destinations for the current). By understanding these basic concepts, you will recognize whatever type of switch you encounter.

The other concept regarding switches that you will encounter with pools and spas is multiple switching. There is often more than one control or switch on each appliance. For example, there might be a wall switch and a time clock, either of which can turn on a pool light. There are often air switches and time clocks controlling spa equipment and a simple on/off switch attached to each appliance so you can shut it off easily for service work.

There are two kinds of circuits and so two kinds of switching. First, switches wired in series are those which operate together. The electric current cannot pass along the line unless each switch is closed. An example of a series circuit and series switches is the control circuit in a heater, where each control switch must be closed before the entire circuit is completed and the ignition of the heater is fired.

The other type of circuit and switching is parallel. A parallel circuit, where there is more than one way for the circuit to be completed, each independent of the other. The drawing shows that the current will reach the appliance if either switch is closed. But closing both is not necessary, and if they are it does not deliver any more or less current to the appliance because both switches depend on the same source of current. An example of parallel circuits and switches is the pool light that is controlled by a switch in the home and by a time clock in the equipment area. By understanding these concepts, you will be able to detect why an appliance is not operating or why it is operating after you turned the switch off.

Relays

A relay is a switching device on a circuit that controls current flow in another circuit. When the relay circuit is electrified, it energizes an electromagnet that pulls the two halves of the relay together. in doing so, the contacts of the controlled circuit are brought in contact, completing the circuit. Relays are normally used as safety devices. The purpose of this type of control is to use a low-voltage circuit (the relay circuit) to turn on or off a higher voltage circuit (controlled circuit). For example, a safe 12-volt circuit can be used near a pool or spa to control a dangerous 220-volt circuit that operates a pump motor or blower.

Relays can also be used to control low-voltage situations, like a millivolt control on a heater cannot be located more than 20 feet from the heater. If you want a heater switch inside your home, for example, you might run a standard 110-volt switch that activates a relay in the equipment area, which in turn controls the low-voltage millivolt circuit of the heater. Relays allow you to run thinner, less expensive wires over long distance. Since the small electromagnet of the relay uses a small amount of current, you can run much smaller, cheaper wires along to control the relay, which can be located near the appliance. The heavier wiring for the appliance only needs to travel to the nearby relay and back.

Relays are just switches so some control and time clock makers include relays in their designs. Instead of requiring you to flip a switch however, the relay turns on or off when powered by electric current, thus turning on or off the appliance.

Testing

Testing for the presence of current at a connection or appliance is simple for you need a multimeter and set the tester on the range of voltage you expect to find and the type of current, ac or dc. The multimeter has multiple functions, testing circuit voltages, continuity, and resistance. It has a positive and a negative test lead and a switching device to set the meter for reading de or ac (reading various ranges of each), resistance, or continuity. The meter is battery powered for continuity and resistance testing because you must send current into a line to test if it is continuous (unbroken) or broken and to test the amount of resistance in a conductor.

When testing the control circuit of a millivolt-controlled heater, for example, you would set the meter for dc current in a voltage range of 0 to 1 volt (since you will be testing a circuit with up to 750 millivolts, which is equal to 0.75 volt). In the same manner, if you are looking for the presence of current at your motor, you set the meter for ac in the voltage range of either 0 to 110 or 0 to 220 volts. Electronically controlled heater circuits operate on 25-volts ac, so you would set the meter for ac in a range of 0 to 50 volts. Generally you can't harm the meter by feeding it less current than the range you have chosen, but you can destroy it by feeding it more. So, if you are uncertain about the voltage being tested, start with the 220-volt range and work down.

When testing dc circuits, remember that polarity (positive and negative) makes a difference. You must touch the positive meter lead to the positive contact of the appliance or switch and the negative lead to the negative contact. If you reverse these, you will see the meter register negative voltage. When testing ac voltage, the polarity doesn't matter, and you can touch either lead to either side of the circuit.

When testing 110-volts ac, touch one lead to the suspected hot line and one to a neutral line or to ground. When testing 220-volts ac, perform the same test on each of the two hot lines, then touch one lead to each hot line at the same time. If each line individually reads 1 10 volts, but when tested together it does not read 220 volts, it means the two hot lines are being supplied by the same phase of the power supply and therefore will not deliver 220 volts. This usually denotes a faulty breaker.

When buying a multi-meter, make sure it can test millivoltage for working on millivolt heaters. Some meters won't accurately read less than 10 volts, and therefore are useless with millivoltage. Most electronic meters are pocket-size and can self-range, which is to say you need only dial in ac or dc and the meter will detect the voltage and adjust accordingly.

When you suspect a broken connection, continuity testing is useful To test continuity of a line, first be sure all the current is turned off, then set your meter for continuity testing and touch one lead to each end of the suspect circuit. If the meter reads positive or beeps, it means there is continuity. Before conducting such tests, make sure your meter is working properly, and that the battery which electrifies the circuit is working, by touching the two test leads together. This should represent a good connection and a complete circuit, and you should get a positive reading.

Since most of the wiring and installation you do uses good conductors, you will probably not use the resistance measuring function of the multi-meter much. If the continuity tester on your meter is not working for some reason, you can use the resistance test to check for continuity. Resistance is measured in units called ohms. The higher the ohms, the more resistance exists in the circuit. If there is no resistance, however, it means there is not a complete circuit, thereby also verifying continuity.

When appliances are operating poorly, there might be a drop in voltage between the panel and the appliance. Check the voltage at the appliance, then at the breaker, while the appliance is operating. There will be a slight difference because of some voltage drop as a result of heat loss and resistance along the length of wire, but it should be no more than 2 to 5 volts. If it is greater, follow the troubleshooting procedures outlined previously to determine where the loss is being created. Like water that is not flowing in a pipe (pressure is the same everywhere in the pipe), when the appliance is not operating, the voltage (pressure) should be the same everywhere along the line.

To test amperage you need an amp probe. The amp probe is a meter with a large, open clip on the end. The clip is looped over the wire and the amperage in the wire is detected by the probe without actual contact with the current.

Electrical work must be prefect and in accordance with local and state codes. So make sure the job is done right.