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GScrimES wrote a new post, What is this IP rating really all about? 6 years, 10 months ago
What is this IP rating really all about? (all)
IP = International Protection Rating.It’s a cool coincidence that it could stand for Ingress Protection – for that is what I suspect most of us […]
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GScrimES wrote a new post, Primary protection of transformers(all) 6 years, 10 months ago
Primary protection of transformers.
For the primary I always simply said:
The control fuse/circuit breaker with a current rating of minimum transformer rating = 1.3xImax that’s it.
The thinking b […] -
GScrimES wrote a new post, What a great question: Sizing of transformer protection. 6 years, 10 months ago
Do you protect the primary or secondary – or both?
This applies to just about all types of transformers, but there are occasions when special considerations come into effect, like safety applications when it is […] -
GScrimES wrote a new post, There is a thief in the electrical system: Power Factor 6 years, 10 months ago
I promise you will never forget this any more!
kW = voltage x current x pfWe say the better the power factor i.e. the closer to 1 the better…
So:
Say 34.4kW= 400V x 100amp x 0.869(pf)
Say 40kW= […]
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GScrimES wrote a new post, Insisting on using a circuit breaker for FULL MOTOR PROTECTION! 7 years, 7 months ago
Basics on selecting a circuit breaker for FULL MOTOR PROTECTION (tech).
**This customer insists he CAN use a normal circuit breaker for FULL motor protection!!
First lets us qualify the title: I am not referring […] -
GScrimES wrote a new post, Circuit breaker cascading/coordinating: – Can you imagine you make a electric short in your house and you trip the whole suburb… 7 years, 11 months ago
It is Saturday night and you are having a grand party…the powerful sound system is tuning out the music…pulling heavy amps.
There comes the drunk uncle…he trips over the self-made extension cord and there […]
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GScrimES wrote a new post, Motor control: Operating a pump more then 200mtrs away? 7 years, 11 months ago
How can one operate a pump over 200mtrs away – with wires?
Yes, can be done with any radio signal but that just an over kill, I think.
Ohhh, you think you can operate a contactor on wires at over […]
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GScrimES wrote a new post, Solid State Relay (SSR) – Do not make this mistake with a 3 phase type 7 years, 11 months ago
When using a 3phase SSR assembly and it has a neutral DO NOT USE A RATING OF 250Vac –
Why?
What happens when the neutral goes missing ?
So ALWAYS select a higher 400-480V devices!
But hang o […]
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GScrimES wrote a new post, How to select the correct relay? 7 years, 11 months ago
Lets start at the basics about this topic.
Application. There are a host of different types of relays for different applications – Solid state relays, Latching relays, Dual coil relays, Stepping relays […]
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GScrimES wrote a new post, Surge arrestors – Should they also have protection fuses/circuit breakers 7 years, 11 months ago
Lets first confirm we are on the same page:- Surge protection gets installed in parallel from the main supply, so it is inevitable that the wire sizes for bigger installations will be an issue for an installer and […]
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GScrimES wrote a new post, Selecting a circuit breaker for motor protection manufacturers(tech) 7 years, 11 months ago
What do we have to consider to use a normal circuit breaker as a COMPLETE motor protection device…startup current/short circuit as well as overload protection.
For a nice introduction to the topic […]
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GScrimES wrote a new post, Selecting motor protection according to regulations(tech) 7 years, 11 months ago
This is pretty deep – For an introduction topic see below link:
If you can’t read this on the screen – similar info is here in our ebook. See here.
What do we have to consider to use a normal c […]
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GScrimES wrote a new post, So Mr. C calls and starts of with:- “Why this rubbish overload does not trip when the current is higher then the motor current?”.[all] 7 years, 12 months ago
At first I am a bit confused…why it does not trip?
So I ask:- Ok help me out here…
What is the overload set at?
Mr. C: 132A
And what current is the motor full load current rati […]
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GScrimES wrote a new post, Is this 100 Amp rated circuit breaker faulty if it does not trip pulling 115 Amps?[mem] 7 years, 12 months ago
An even better/trickier question to ask is: If I pulled 100 Amp through a 100 Amp circuit breaker will it trip?
If you said yes then you must hang around this site much more frequently.
Truth is that the […]
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GScrimES wrote a new post, Selecting a circuit breaker according to load current – tech 7 years, 12 months ago
Select a circuit breaker according to the load current – what does the rules actually say?
There is an introductory post to this topic here -less technical..
Please note: The following information is my […]
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GScrimES wrote a new post, Circuit breaker- Can it be mounted upside down?(tech) 7 years, 12 months ago
Circuit breakers regarding mounting(electricians) upside down.
What does the regulations say?
SANS 2012
IEC
NEC6.8.2.3
It is forbidden to mount a cb upside down.
Who would want to do […] -
GScrimES wrote a new post, Can I connect a circuit breaker coming in from the top or the bottom – as I prefer? cont. 7 years, 12 months ago
Can I connect a circuit breaker coming in from the top or the bottom – as I prefer?
From a regulations point of view it is allowed BUT ONE HAS TO ENSURE THE PRODUCT DOES NOT HAVE SUCH A LIMITATION…IN FACT […]
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GScrimES wrote a new post, Circuit breakers: Can I come in from top or bottom as I prefer 7 years, 12 months ago
Is it allowed to connect the supply to a circuit breaker from the top or the bottom?
All the standards I have come across allows this.
If the product is confirmed capable of doing so, it is allowed
The […]
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GScrimES wrote a new post, AC circuitbreakers in DC circuits cont. 7 years, 12 months ago
I bet you did not know that those AC circuit breakers can be used for DC applications
In fact in the definition for a circuit breaker in the regulations accounts for both ac and dc specifications.
There is […]
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GScrimES wrote a new post, Circuit breakers: What is the difference between overcurrent protection and overload protection? 7 years, 12 months ago
Overload current is any current higher than the design current based on the connected load of the circuit, and not due to circuit or component failure.
As such – Overload protection is set according to the […] - Load More
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