What is the purpose of a timer wired into the compressor contactor control circuit on a refrigeration system?
A defrost control typically.
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Answer . it is the switch turns the compressor on and off if you look in your unit follow the power wires from disconnect the should go straight to the contactor
There is a relay for the A/C, as well as a fuse in the fuse panel. Start by checking these to to see if they have power and the fuse is good. There is a single green wire that connects the compressor to the wiring harness, plus there should be a body ground bolted somewhere on the A/C frame. all the…se need to be connected and in good condition. Depending on the year you may also have wiring connections at the dryer that senses the pressure, if it is too low, it will keep compressor from running to protect it. Additionally, the switch in the dash has two wires (usually) connected to it. FOr wiring diagrams the best bet are the green covered Volvo service manuals. They are still available new from volvo, or used at auction sites online. (MORE)
The purpose of the bus bar protection unit is to isolate any bus by tripping its contactor or isolate a faulty bus in the variable ac system?
NO, it sounds like your asking about the protection and isolation of the Bus Bar. . The Bus Bar is (usually 3, or 4) solid copper bars that run through an MCC (Motor Control Center) and just supply power to the individual 'buckets' (compartments that contain the individual motor starters).. The …only protection for a bus bar would be from the 'Panelboard', or 'Switchboard' breaker that feeds the bus bar mounted in a separate MCC. Make Sense???, let me know if not... (MORE)
A circuit breaker is designed to break a circuit which is carrying current at the time. Where large currents and/or voltages are present, the opening of the circuit may induce dangerous arcing, so means such as air blast must be used to "blow out" the arc. Air breakers are being phased out and repla…ced with vacuum or SF6 breakers. An isolator is only designed to isolate a circuit or other component after the current has already ceased, so it doesn't need to have any means to stop the arc. Thus in high voltage/high current installations such as in power stations or grid switching stations, the initial operation to isolate the circuit, whether planned or as a result of a fault, is by the circuit breaker, the isolator is then used to isolate the circuit breaker for maintenance or repair. The difference between a circuit breaker and a contactor is that a circuit breaker can break fault current while a contactor cannot. A contactor is typically implemented in series with a fuse which serves to interrupt fault current. An isolator and a contactor are not synonymous. (MORE)
sirs if you could explain me detail about the staircase lighting ckt diagram & explain how does the switch function.
\nRelatively simple. There are two power contacts, you wire the two wires for the line you want to interrupt or connect to these contacts. this is for the simplest type, SPST, one set of contacts to switch a power line on when the control signal is on. There are more complicated contactors with mult…iple sets of contacts.\n. \nThere are two connections for the control circuit which are typically low voltage AC or DC. Connect these to the control signal, ie, the signal you will use to turn the contactor on or off. (MORE)
A CONTACTOR SHOULD NOT BE USED TO START A 3-PHASE MOTOR unless there is some sort of motor protection in series with it. You would need a 3-phase contactor and just connect each phase (1 wire) to each terminal of the line side of the contactor, and the 3 wires to the load side. 3 wires on the line s…ide, and 3 wires on the load side. (MORE)
A three pole contactor is wired with the line voltage connected to the top terminals L1,L2,L3 and the load connected to the bottom terminals T1,T2 and T3.
It is relatively easy to wire a single phase contactor that is controlled by a pir in a lighting circuit. Take the two wires for the line that is to be interrupted or connected and attach them to the two power contacts. If this is too complex please get some help from an electrician as working with …electricity can be very dangerous. (MORE)
A mechanical compressor is a device which compresses fluid. It is used to create differences in presssure which creates movement in said fluid. The compressed fluid also has more energy, and thus more uses than expanded fluid.
\nVoltage stabilizers are the circuits that are used to filter noise from the source voltage. DC voltage generated from a bridge network or diode network will contains voltage glitches. These glitches may cause serious problems to the operation of digital circuits. So a voltage regulator is used to …filter these glitches. voltage stabilizer can be built using a voltage regulator ICs like 7805 for +5V, 7809 for +9V, 7905 for -5V, 7909 for -9V and so on. (MORE)
Timing is complicated in electronics, and there are only a few good solutions. You should use a microprocessor called the LM555 timer (or just the 555 timer). While seemingly daunting at first, this small 8-pin device affords a lot of features and can perform one-shot timing (press a button and k…eep a light on for a certain time determined by the resistors and capacitors), astable timing (essentially generating an on and off signal), bistable timing (controlling two lights; one on and one stage, and one on at another stage), and with some clever 'hacking' it can be used to encode an analog signal into a PCM (pulse-code modulation) signal, often used for devices such as remote controls and toy aircraft. A quick overview: There are the pins 4 and 8 which should be powered. When you use pins, you count from the bottom left, which is indicated by the small indented circle in the chip. Pin 1 should be connected to the negative end of the battery or power supply. The chip can run from 2 volts to up to 14 (some chips support 18) volts but for something like an LED, 9 volts should be good (a different voltage would mean you'd need a different resistor for the LED). Pin 5, optionally, should be connected through a small capacitor (100nF or near) to the negative end of the battery; the capacitor should not be electrolytic. This is optional as it just helps settle the value on one of the internal comparators and makes the timing more accurate. Pin 7 should be connected through a 10k resistor to positive. Pin 6 should be connected to pin 7. At the end of this series, you should connect a capacitor, which determines the timing amount (as well as the resistor). The second capacitor should be about 100 to 220 uF, which will give you a range of 1.1 seconds to 2.42 seconds. You can of course adjust to any value suited. Pin 2 is the trigger. A 10k resistor should be wired though a push-to-make switch, connected to the negative end of the battery. Then, the positive end of the push-to-make should be wired into pin 2. Pin 3, the last pin, is the output. Wire a 330 ohm resistor and a green LED into this and you are set. Wire the end of the LED to ground (the negative end). Press the button, and it should work, timing for the value of the capacitor. The formula for the time is T=1.1(CR) where C is the timing capacitors' value (C being in farads, and it will be very small), and R being the resistor connected, in ohms. This will be the larger value. The 1.1 multiplication is just because of how the timer works. The whole circuit can be build on a breadboard/prototyping board. Or, if you have the skills, you can build it on a printed circuit board. It should be noted however, this timer is not 100% accurate. Because of component tolerances, you should allow for as much as 17.5% inaccuracy in both directions. If you need more accuracy, you need to get into the very complicated world of quartz crystals, real-time clocks and the like; and even they suffer from 'clock drift' (being incorrect by up to 30 seconds a month depending on temperature). In short, if you need accurate timing, you need an atomic clock! There are many resources on the web for how to do this. Simply use Google or your favourite search engine to search for '555 timer'. (MORE)
Diagrams are unavailable in this Q & A format. A good diagram source is Sq D Wiring diagrams, see sources and related links below. This book has a wealth of information for anyone that does electrical control work.
The wiring in most homes consist of three wires Two wires make up an electric circuit What is the purpose of the third wire?
A short answer to this question is: the purpose of the third wire is that it is installed to provide a safety wire that will carry any ground current if a fault condition occurs. For more complete information please see the answer to the Related Question shown below. There are two main t…ypes of cables used in home wiring for the secondary branch circuits. One is a two wire cable and the other is a three wire cable . Whenever these cables are referred to, the bare ground wire is not included in the wire count as it is not a current carrying conductor. Most predominant is the two wire cable used for most circuits. The use of the three wire cable is for split kitchen receptacles and wiring of three way switches. In a big sq foot area home, three wire cables are sometimes used to take two circuits to the other end of the house instead of using 2 two wire feeders. These types of circuits use the common white wire for the neutral and the red and black wires for the two hot circuits. As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed. Before you do any work yourself, on electrical circuits, equipment or appliances, always use a test meter to ensure the circuit is, in fact, de-energized. IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB SAFELY AND COMPETENTLY REFER THIS WORK TO QUALIFIED PROFESSIONALS. (MORE)
A definite purpose contactor is designed (and rated) for a specific load. So a lighting contactor is one example of a definite purpose contactor. A motor starter contactor is another example.. So, a lighting contactor is a definite purpose contactor, but a definite purpose contactor is not necess…arily a lighting contactor (it might be a motor starter, for instance). (MORE)
The wiring in most homes consists of three wires Two wires make up an electric circuit What is the purpose of the third wire?
The standard colour coding for UK electrical wiring is: Live -Brown. Neutral - Blue. Earth - Green and yellow stripe.
It's much easier than you think, all you need is some tools and some electrical experience. First of all you need to take off the compressor and check the electrical wires, modify them in order to be able to just plug them in AC outlet, be careful, don't take out any piece, there's a capacitor that …should stay on one wire in order to make going easier, when you're done, plug it and check all pipes coming out of the compressor, you need to find two pipes, one is pumping air and the other is vacuum ( close it with wet finger it should feel like sticky ) then, when you find these two pipes, close all the others ( if there is ) by bending or any other way, then just attach a high pressure plastic tube to the pumping pipe and done. (MORE)
Not always. But if a compressor goes bad it can take out the contactor. I have replaced compressors before and found the contactor is still ok.. In a commercial application Copeland will not honor the warranty if the contactor is not replaced at the same time a new compressor is installed. Not sure… about residential but for a $15 contactor I would not gamble with it. (MORE)
Explain the purpose of the simple and hold circuit in a computer controlled data acquisition system that uses a ADC?
I presume you mean "sample and hold"; to read a voltage an ADC takes a finite amount of time - if the voltage changes during that time, then a misreading can occur. The sample and hold keeps the voltage seen by the ADC constant during the reading time.
A timer is often used in a heated rear window function to stop the circuit from over heating and blowing a fuse if forgotton about.
You need a double pole relay, that is a relay with 4 connection places. [screws, etc.]. Place your 2 hot wires on the screws marked line, makes no difference which wire on which screw. The 2 wires being energized by the relay action go on the load screws of the relay. Square D makes a good quiet rel…ay. Also make sure you buy a relay large enough to carry the load. The amperage on the device the relay is to control will determine the relay size.. See View Discussion for more information. (MORE)
One way is to use the auxiliary contacts on the motor contactor to close a separate source supply to drive an auxiliary relay.
Depends on where you want to put it! Assuming, that you're asking ~how you'd "install" a Definite purpose contactor.
It's one of the most common error codes which you can run in if you own Toyota Camry. It's well known that presence of such code does not mean that something is wrong. First try reseting the computer. If the code comes back than you have to change the sensor. The sensor is usually attached to the ch…arcoal canister. If you get it from Toyota dealers it's about $170. Sometimes you can find cheaper on eBay.com (MORE)
A contactor not being energized or closed can be caused by a host of reasons . A shorted or open contactor coil. No control voltage or incorrect voltage present to energize the contactor coil , A safety device opening or breaking the control circuit . A loose or broken control devise or control wir…e . and possibly more , depending on your a/c units control wiring configuration. Tom H, HVAC proffesional. New Orleans . (MORE)
A circuit breaker is a protective device that interrupts current flow in a fault condition. It is not intended for routine use to turn the load on and off A contactor is a controlling device that turns the current flow on and off to a load. It is not intended for use as the protective device. A… circuit breaker will have a contactor of some type in it. The key here is the circuit breaker is designed to interrupt fault current, while a contactor may be designed to interrupt load current (substantially less). Circuit breakers are much larger than their equivalent contactor / switch, because they are designed to handle the excessive heating that naturally will occur when breaking substatial amounts of current flow. (MORE)
There is not a huge difference between C.B. and contactor as they work as a switches but usually CB is normally closed while there a normally open/closed Contactor. the Contactor used only in a control circuit while CB is used on large power system utility, such as substations. Contactor receive an …electrical signal from relay while CB need an auxiliary contactor to trip. Most of the CB needs a arc quenching fluid such as oil, SF6 and vacuum..etc. (MORE)
This depends on the circuit. A resistor may be connected in series with a capacitor and will control the rate at which the capacitor charges or discharges (known as an RC timing circuit); at a certain voltage (0.6 Volts) this may turn on part of another circuit through a transistor.
The wire in a circuit acts like pipes directing water from one location to another. Wires carry the current.
If the contactor is held in mechanically there would be no coil used to hold the contactor in, therefore no wires to operate no coil.
it compresses the refrigerant vapor into a small volume, increasing the pressure and therefore the temperature of the refrigerant The compressor moves the refregirant around the system. With nocompressor, refregirant will not move at alll, and for the airconditionor moving the refregirant is essenti…al. (MORE)
No wires are needed to control a mechanically held contactor. An electrically held contactor will require two wires to control it.
As of 2014 all refrigerators must be on a GFCI protected circuitand it must be readily accessible. If you wire the refrigerator ona 15 amp circuit using AWG #14 wire it must be on a dedicated GFCIprotected circuit, no exceptions. As you will normally mount theoutlet behind the refrigerator you would… have to move the unit toreset the breaker if and when it tripped. I would wire therefrigerator on one of the 20 amp kitchen counter-top circuits thatis GFCI protected. Now, my answer may be debatable but from how Iread the NEC code you can wire it to one of the kitchen branchcircuits as long as the refrigerator does not pull more than 16amps. You might want to check with your local inspector to get hisopinion as he is the one who will have the final say. (MORE)
Control means, a timer cant control is speed directly, it can control its operation. A times will have NO nd NC contacts. Connect the motor in series with the timer contacts wrt desired operation
A contactor is wired with the line voltage connected to the top terminals and the load connected to the bottom terminals. A second circuit is used to energize the contactor coil to draw the contactor's contacts together to complete the circuit to the load.
Timer relays are used in control circuitry. There are two main types, an (off delay) and an (on delay). If you want one device to turn off before the timer controlled device then you would use an off delay timer. If you want one device to turn on before the timer controlled device then you would use… an on delay timer. When the timer is energized this starts the timer circuit in the relay to time out. (MORE)
They can be used for electrical loads with heavy current that need to be switched on and off. They are also used for remote switching applications.
Oil in a AC compressor is there so that the mechanical parts don't over heat from friction
A closed loop system is one where the ouput of the system is at least part of the input. In a refrigerator, the output of the cooling system (the cold air inside the refrigerator) is measured, and is fed back into the system to determine whether the system needs to continue cooling. An example of a… fridge that was an open loop system would be one that turns on and cools for 1 hour every 6 hours, regardless of internal temperature. (MORE)
Presumably, you are asking the purpose of a neutral conductor , rather than 'contactor'? A alternating-current supply has two conductors, a line conductor and a neutral conductor. The line conductor is at system potential (e.g. 230 V in Europe), whereas the neutral conductor is at approximatel…y earth (ground) potential because it is earthed (grounded) at the supply transformer. The neutral conductor acts as the 'return' path to the transformer, carrying the same load current as the line conductor. (MORE)
A contactor is nothing more than a switch but it is electrically operated instead of mechanically operated as you would find with snap switches in your home. As with any switch, you need to make sure it is rated for the voltage and amps you intend to feed through it. You will have a pair if termin…als for each hot wire. In addition you have terminals for the coil that operates the contactor. Very often this is a smaller voltage but not always. These control wires may be connected to any piece of control equipment, which may be a snap switch, but may also be a thermostat, light or motion sensor, or various types of hydraulic sensors such as pressure, flow, or float. In today's technology the coil may be activated by computer signal which may be reading many different conditions. (MORE)
A timer is a type of contactor. My answer assumes you do not need an additional contactor besides the timers and the timers are operated by the same circuit as the outlet. Each timer and the outlet need connections to the neutral and grounding conductors of the circuit. For the hot wires, you hav…e to run your hot feed to each of the timers on the "line" side of the contacts. If the timer and the "line" side of the contacts are different connections you will have 2 connections in each timer. Then from the "load" side of the contacts you run wires that connect to the hot side of your outlet. At some point you will splice these together so you have only one hot wire connection to the outlet. Remember that timers, contactors, relays, etc., are simply switches operated by various means. You have the hot feed on one side and the "switch leg" to your load. You also have a control of some kind, and in your case your controls are the timers. (MORE)
When using a 3 wire control circuit to control a magnetic motor starter the part that will open the control circuit when an overload occurs will be?
The part that opens the circuit is the overload blocks that are situated below the magnetic starter and before the motor load. The latest addition to the electrical code book states that the "hot" wire goes through the overload contacts first before feeding the 3 wire control system. With the supply… voltage in this position the whole circuit becomes de-energized when the motor load trips the circuit. The old standard practice on a 3 wire control system, the neutral was connected to the overload relay contacts. When the overload relay tripped it opened the neutral of the coil circuit and the starter dropped out (MORE)
air contains moisture & suction line is very cold both in contact moisture turns into ice. just a joke
When a household refrigerator compressor does not run it is recommended that low and high side access valves be installed when recovering refrigerant from the system because?
The last thing you want to do is tap into a closed system, this is the beginning of the end in most cases. If a unit is damaged, the refrigerant will be gone anyways. A refrigerator holds 4 oz. to 5 oz. refrigerant, it takes a tiny leak to deplete it entirely. Should you need to pump a system down t…hen you can install a tap temporarily and sil floss in a proper suction line access, the high side is optional. (MORE)
A contactor is a type of switch. However this switch uses electricity to power an electromagnetic coil to switch on or off power. Hence a contactor needs 2 wires - A live/hot wire and a neutral wire. Generally these are connected across the A1 and A2 terminals of the contactor.
A timer can be of two types. An off-delay timer is used when the circuit needs to be energized for a specific amount of time after the off-delay's timers coil becomes de-energized. An example of this is when a cutoff saw becomes de-energized but the conveyor, to move the wood along, needs to be oper…ational until the wood clears the saw head. The other type of timer is an on-delay timer. An on-delay timer is used when you don't want all of the equipment to come an at once. After a power failure, in motor circuit starters you don't want to create a high inrush to the MCC (Motor Control Center) when all of the motors try and start at once. This high inrush could trip the MCC breaker an then none of the motors would start. Each motor module has its own on-delay timer so that the motor starts are staggered. The first motor will start, when the on-delay timer of the second motor times out, it will start, and so on until all of the motors are back on line and running again. (MORE)
-To enter a cell at a specific receptor site -Cause an internal reaction which maintains homeostasis
The purpose of a management control system is to allow an operator to perform multiple tasks at once, as well as measuring and analyzing a large amount of tasks at once, to represent an overall performance of a given system or machine.
Fly by wire is a semi-automatic and/or computer-regulatedsystem for controlling the flight of an aircraft. This different tothe old aircraft that had pullies and cables attached to thecontrols and this made it physically demanding for pilots. The useof computer aided motors and hydralics make it eas…ier and allowsmany of the control functions to have preset automotive capacityi.e using the autopilot is not much easier when used with a FMS(Flight Management System). (MORE)