Pl. see http://www.worldproducts.com/MOVDefinitions.htm
You use varistor wich has the max voltage for that aplication example:vacuumcleanermax allowed voltage is 240v ac so you chose aprox. 250 V varistor.
How i determine correct size varistor for protect system which work with 220 v AC?
is this coil a single shot solenoid or is it used as a filter i assume you want to know a good value for a varistor to stop voltage spikes from the reverse EMF which is aprox. 4X the input voltage. so i would say to use 2X-3X the input Voltage so 48 or 72 Volt MOV (Metal oxide varistor) You want the varistor to be several volts greater than the peak voltage of the signal across which it is connected. 24 volts is probably the RMS value of the coils voltage. Your varistor must be selected to be greater than the peak voltage. When the voltage exceeds the clamping voltage of the varistor, it conducts current, preventing the voltage from reaching a dangerous level. If the elevated voltage is maintained for too long a time, the varistor will heat to a point where the metals in it melt and fuse together, causing a short. This also poses the posibility of a fire risk, as the current is now conducting heavily through the varistor. This is what often happens to a varistor in a power strip when lightening strikes nearby. It renders the power strip useless. But the connected devices are usually spared.
Operating system
A varistor is an electronic component used for surge suppression. It is also known as a voltage dependent resistor, but it acts more like two zener diodes reversed and placed in parallel. The majority of surge suppression devices use these. However, they don't work all that well for lightning strikes.
You use varistor wich has the max voltage for that aplication example:vacuumcleanermax allowed voltage is 240v ac so you chose aprox. 250 V varistor.
transient varistor
How i determine correct size varistor for protect system which work with 220 v AC?
I think your answer is given in previous question -( correct size of varistor across 24v coil) I am just pasting the same here. . . "When the voltage exceeds the clamping voltage of the varistor, it conducts current, preventing the voltage from reaching a dangerous level. If the elevated voltage is maintained for too long a time, the varistor will heat to a point where the metals in it melt and fuse together, causing a short. This also poses the posibility of a fire risk, as the current is now conducting heavily through the varistor. This is what often happens to a varistor in a power strip when lightening strikes nearby. It renders the power strip useless. But the connected devices are usually spared. "
Varistors are not polarity sensitive. Now I'm pretty sure that the device in question is a varistor. I googled for SAS-820KD05, found several references but unfortunately no data sheet - maybe you have more luck. One main criterium for selecting a varistor is the varistor voltage - as long as the voltage applied to the varistor is below the varistor voltage, it will behave like a capacitor. When the voltage is above, e.g. caused by a transient, it acts as a resistor, shorting this transient. Another important value is the max. pulse current a varistor can withstand.
A varistor is installed onto the "line" and "Neutral" wires of an AC power input.Added:Maybe this will help you more: cf. Related links, just below this answer page.
is this coil a single shot solenoid or is it used as a filter i assume you want to know a good value for a varistor to stop voltage spikes from the reverse EMF which is aprox. 4X the input voltage. so i would say to use 2X-3X the input Voltage so 48 or 72 Volt MOV (Metal oxide varistor) You want the varistor to be several volts greater than the peak voltage of the signal across which it is connected. 24 volts is probably the RMS value of the coils voltage. Your varistor must be selected to be greater than the peak voltage. When the voltage exceeds the clamping voltage of the varistor, it conducts current, preventing the voltage from reaching a dangerous level. If the elevated voltage is maintained for too long a time, the varistor will heat to a point where the metals in it melt and fuse together, causing a short. This also poses the posibility of a fire risk, as the current is now conducting heavily through the varistor. This is what often happens to a varistor in a power strip when lightening strikes nearby. It renders the power strip useless. But the connected devices are usually spared.
Bisque or Oak, depends on what people interpret it as.
Operating system
Metal oxide varistor
varistor (yes, that's a word)
that depends on the year of mfg. the code changed frequently