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If when a relay is energized you measure 0.05 VAC across a set of normally open contacts the?
Wiki User
∙ 6y ago
If, when a relay is energized, you measure 0.05 VAC across a set of normally open contacts, the
Wiki User
∙ 6y ago
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What is the purpose of a thyrector diode connected across normally open contacts?
To suppress transients from switching currents to possible inductive loads.
Should your panic button be wired to the no or nc terminal. It doesn't say in the instructions.?
If the circuit of the panic button is monitored for a break in its circuit, the contacts will be in a N.C. configuration. There will need to be a relay in the circuit that is kept energized by the buttons closed contacts. When the relay drops out, its N.C. circuit contacts will activate the panic buttons load. If the panic button has no monitoring features then the contacts across the button will be wired in the N.O. configuration. When the button is pushed the circuit closes.
Why is the voltmeter is placed across the load to be measured?
Because that is what you are trying to measure.
How do you prevent arcing in electrical contacts?
Arcing is caused by current trying to sustain its flow by using the air as a conduit. If the travel is very far the arc will dissipate as lack of paths. If the current is great it may sustain itself. All contactor have a biult in shoot trough to channel the energy harmlessly, A capacitor across the contacts can help by absorbing the difference in voltage when the contacts disconnect or connects
How does across the line starting work?
There are mainly two types of starting methods. Reduced voltage starting and across the line starting. Reduced voltage starting comes in the configuration of the wye-delta starter. Across the line starter is the combination of voltage source, motor contactor and motor load. The utility company's policy is set, to allow only a certain horsepower load to utilize across the line starting. This is in the neighbourhood of 25 HP up to 50 HP. High horsepower loads draw high current, up to 600%, of the motors full load rated amps. This high current inrush tends to draws the line voltage down and to prevent this condition wye-delta starters must be used. In the electrical market today solid state soft starts have taken the place of wye delta starters. When using a three phase contactor across the line for motor starting, a three phase overload block must be used. The wiring of the contactor consists of taking L1, L2 and L3 of the supply voltage and connecting it to the top of the contactor on terminals L1, L2 and L3 of the contactor. The motor load is connected to T1, T2 and T3 on the bottom of the overload block. If you are using a three wire control for operating the contactor, the contactor must have a N.O. contact on it to seal the contactor in once the contactor coil has been energized. The overload block has three N.C. contacts, one for each leg of L1, L2 and L3. These three contacts are wires in series to the stop - start circuit. Years ago on old schematic diagrams these contacts used to be placed on the down stream side of the magnetic starter's coil (between the coil and the neutral). When the overloads tripped the voltage was left on the control circuit which was found to be dangerous for trouble shooting. Now for safety reasons, the overload contacts are positioned in the beginning of the start- stop circuit so that when a overload trips, the whole stop - start circuit becomes de-energized.
What is the purpose of a thyrector diode connected across normally open contacts?
To suppress transients from switching currents to possible inductive loads.
What are normally closed Switch?
this means having a low resistance measurement ; average 0.5 ohms, across 2 contacts of a switch which is normally a low value or short circuit when the switch is physically closed.
Should your panic button be wired to the no or nc terminal. It doesn't say in the instructions.?
If the circuit of the panic button is monitored for a break in its circuit, the contacts will be in a N.C. configuration. There will need to be a relay in the circuit that is kept energized by the buttons closed contacts. When the relay drops out, its N.C. circuit contacts will activate the panic buttons load. If the panic button has no monitoring features then the contacts across the button will be wired in the N.O. configuration. When the button is pushed the circuit closes.
How can you include phase failure relay in your star delta motor starter circuit?
The star delta motor starter circuit has to have a control voltage to energize the motor magnetic contractors. A phase failure relay monitors all three phases of the incoming supply lines. The phase failure relay also has auxiliary contacts on it. There are usually two sets of "C" form contacts. The control voltage for the starter circuit must be connected across the normally open (N.O.) contacts of one of these two sets. When the phase monitor is energized these N.O. contacts close supplying the control voltage to the circuitry of the star delta starters. If there is a phase interruption, phase reversal or phase loss, the phase failure relay will de-energize and the N.O. contacts will go back to their de-energized state. If the star delta motor starter is in use at the time, its control circuitry voltage will be lost and the delta motor magnetic contactor will open. The opening of this contactor will disconnect the motor from the failed three phase supply.
How do you read an electrical schematic drawing?
schematic drawings explain electrical circuits. First you must know the basic requirments for any curcuit. 1. All circuits must do work. ( without a load the wiring becomes the load and it burns up. This is known as a short circuit. 2. All circuits must have an electrical path. From a voltage sourse to a load and back to the source. 3. There must be a way to control the electrical force. for example to turn it on and off. When looking at schematics there are essential questions you should ask yourself. What is the intent of the circuit? How is it controlled? Where is the load? What is the load? Where is/are the controlling switches...etc? Is the contol voltage the same as the load voltage? What coil controls what contacts? Schematics are often laid out as ladder diagrams. These show each simple circuit one at a time. IF they are now laid out a ladder diagrams many find it useful to redraw the schematics to put them in that form. Schematics use symbols it represent different parts of the circuit. Often circles will denote a coil portion of a relay (or automatic switch) Often there will be a letter in the circle to identify the coil. That letter will also be assigned to sets of contacts that that coil operates. Contacts can be NO normally open or NC normally closed. Normally closed means that there is an electrical path across the contacts when the coil is not energized. Normally open means that the switch is off or there is no electrical path across the switch when the controlling coil is not energized. This is a long subject and I will add to it from time to time. and any who know the subject are invited to add information to this answer as they wish. \
How would you get the message across that Vodafone offers cheaper text to its customers?
text it to everyone in ur contacts then tell them 2 forward it to everyone in their contacts
How would you measure a relays contacts resistance?
The voltage drop across a relay coil will be the same as the coil supply voltage. If you are trying to see if the coil is good or not, remove one of the voltage supply leads and check for continuity by using an ohm meter across the coil leads. A reading will tell you that the coil is intact and not open.
If 120V is present on a120V relay coil what will the voltage reading be across the closed set of relay contacts on a 120V circuit?
0v The relay is designed to act as a switch when voltage is applied across the coil. The contacts open or close but only pass through whatever is connected to those terminals. <<>> When a relay coil is energized the relay's contact change status. The closed set of contacts will open. The 120 volt circuit that is connected will turn off. As to the voltage at the contact terminals, it depends on where you are taking the voltage reading from and to. On the source side of the terminal there will be a reading of 120 volts to neutral or ground. On the other side of the contact terminal there will be zero volts to the neutral or ground. This is because that wire is in series with the load to neutral. A meter reading across the relay terminals will read 120 volts.
Do You measure current across a circuit?
A current flows through, not across, a circuit. And, yes, you can measure it using an ammeter.
Which will normally have the larger resistance a voltmeter or an ammeter?
A voltmeter has the large resistance.The voltage across any component can be measured if & only if the terminals of that component will be open and this will we can acheiv if we connect the high resistance voltmeter across the open terminals of that component to measure the voltage.
Where can I purchase contacts online?
Coastal Contacts online is exactly what you are looking for, They distribute contact lenses across the country and boast claims of saving you 70% on most lenses.
What way does blood normally pass across the placenta?
blood does not pass across the placenta
