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I think I used to know this 😳 but it’s lost in the profound depths of my enormous brain 😆 .
Mike.Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
Are you sure? It’s embossed in the plastic on a single pole switch 😕
Mike.Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
So on a single pole switch I should find the inscription (4) and a double pole switch (8 )
Ok, thanks Tim, I’ve just had a look at a few, and that seems to work, more or less.
MikeRe: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
the (4) would normally indicate the max-resistive load you can load the switch.
For example, 16= 16A for resistive loads
4=4A for non-resistive loads such as motors, transformers and the like.The reduced rating is normally to allow for the extra stress due to contact-arcing caused by the non-resistive load
Regards
Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
A correction (its late!!)
the (4) would normally indicate max NON-resistive load you can switch with the switch……. 😉 etc etc
Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
This is getting interesting! Three answers so far, all different! Back to my bag of switches to check out this new one. (Though not right now, I’m determined to get some sleep.)
Mike.Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
I wish I had concerns as trivial as that to keep me awake. 😆
Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
Brains wrote:the (4) would normally indicate the max-resistive load you can load the switch.
For example, 16= 16A for resistive loads
4=4A for non-resistive loads such as motors, transformers and the like.The reduced rating is normally to allow for the extra stress due to contact-arcing caused by the non-resistive load
Regards
a motor not a resistive load then?
Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
Eastlmark
Motors are not resistive loads. They are normally considered as inductive.
The only time thay could be considered as nearly resistive, is, if they are run from a dc source. However, if you or I wanted to get picky :rolls: at start-up, or, power-down, they could be considered as inductive
Regards
Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
Resistive Load is an electrical load which is characteristic of not having any significant inrush current. When a resistive load is energised, the current rises instantly to it’s steady-state value, without first rising to a higher value. An electrical load in which voltage and current are converted to energy in the form of heat; i.e., an electrical heater, incandescent bulb.
Inductive Load is an electrical load which pulls a large amount of current (an inrush current) when first energized. After a few cycles or seconds the current “settles down” to the full-load running current.
The time required for the current to “settle down” depends on the frequency or/and the inductance value of the Inductive load; i.e an electric motor, electromagnet.Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
Which type of load is a transformer?
Mike.Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
A conventional wirewound transformer is considered as inductive.
A complication with some transformers is that the magnetising current is at the third harmonic.
This can cause interesting issues 😉
Regards
Re: Switch ratings. e.g. 16A(4) /250V ac. What is the 4 for?
Phidom wrote:I wish I had concerns as trivial as that to keep me awake. 😆
😆 I guess I’m just so lucky.
On the other hand, not so trivial if it allows you to better understand the job you’re doing. As the Chinese saying goes, “knowledge is wealth you carry with you.”
Mike.
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