u/charzr

Can somebody explain the operational sequence of these key interlocks?

https://preview.redd.it/15flz73pvo0h1.png?width=1047&format=png&auto=webp&s=c862083a2935c2e6af1c3e66ef9b43bcbebcd4cc

What is the minimum IP rating required for an enclosure to direct the exhaust of extremely hot gases from an internal arcing event away from personnel?

(or)

In the case of a non arc rated enclosure, which IP rating provides optimal protection against arc flash for personnel in the vicinity?

What is the minimum IP rating required for an enclosure to direct the exhaust of extremely hot gases from an internal arcing event away from personnel?

(or)

In the case of a non arc rated enclosure, which IP rating provides optimal protection against arc flash for personnel in the vicinity?

DOI: https://doi.org/10.1109/PCIC47468.2025.11289199

How do I read this curve?

What info do i infer from this curve?

https://preview.redd.it/h601f89njxzg1.png?width=1139&format=png&auto=webp&s=a285d39ec41355f497f0c87b256ad2af53b419e2

How do I read this curve?

What info do i infer from this curve?

https://preview.redd.it/utxbkieaixzg1.png?width=1139&format=png&auto=webp&s=9f277005365219a1d7c5b36ec4dc6fc4c187fee2

How do I read this curve? What info do i infer from this curve?

https://preview.redd.it/askfx9cvhxzg1.png?width=1139&format=png&auto=webp&s=47ddc08f6ec2fcb62d5998d5f1b334920da165e6

DOI: https://doi.org/10.2118/217592-MS

How do you decide which motor(s) should start in the first sequence (SQ0), second sequence (SQ1), SQ2, and so on?

What is the rationale behind this sequencing?

What key questions do you ask yourself while preparing the sequence table?

For Rack out:

Push the pushbutton in the IED - Which will unblock the magnet/solenoid (unblocks the rack in/out mechanism)

Bring it to isolated position within 30 seconds, else the magnet/solenoid locks it

What is the rationale behind the blocking/unblocking magnet and the time delay of 30s?

I understand it brings safety, but how? why this is done?

Similarly there is a push button name "Earth switch unblock", after pressing it, timer is enabled

after some time the earth switch magnet/solenoid is energized and permits to insert the lever of the earth switch.

Why is it done?

Do you provide dedicated undervoltage protection for low voltage motors below 100 kW?

My understanding is that, in this power range, undervoltage is typically addressed by the overload relay, since a drop in voltage leads to an increase in current.

In such cases:

Should undervoltage protection be provided at the MCC incomer (fed from HV/LV transformer)?

(Or)

Is it acceptable to leave it as is, as the upstream (high-voltage side) breaker will trip on undervoltage?

Website: https://ieeexplore.ieee.org/document/5525753

Is the red rectangled area correct location for the installation of Ammeter?

This is the Electrical Star-Delta starter circuit

https://preview.redd.it/zht1yqis05zg1.png?width=453&format=png&auto=webp&s=6817eff64f40d7cad41b9ea265b94f2f7ae4769b

For Medium voltage switchgear - Do you trip the breaker on Trip circuit supervision unhealthy and on Internal relay fault alarm?

For Low voltage switchgear - Do you trip the breaker on Trip circuit supervision unhealthy and on Internal relay fault alarm?

Office location: The Earth Centre by Vista Spaces, Whitefield.

Looking for 1BHK / studio / single-sharing PG / nearby terrace room.

Any leads?

Office location: The Earth Centre by Vista Spaces, Whitefield.
Looking for 1BHK / studio / single-sharing PG / nearby terrace room.
Any leads?

What is preferred for penetration of cables via draught stops above ceiling in the accommodation? MCTs or putty compounds. The concern for the putty is in future if i have to install / replace the cables, there is a quite a lot of work to do, however for MCTs, when installed will have spare entries.

Do you have sockets in the low voltage compartment of switchgear (LV or MV)? If yes, what is the purpose of these sockets:

Only for laptop charging during commissioning?

For use with testing kits as well?

For vacuum cleaning the panels when the main power is isolated?

The switchgear manufacturer has not provided one, stating that it is not included in the specification

I understand that EDG is supposed to run till destruction; then why differential protection is provided? or during differential protection is EDG intended to trip?

Does this rotary handle move to the Trip position, or only to the Open position?

https://preview.redd.it/styyb98jrgxg1.png?width=2012&format=png&auto=webp&s=25afe857dc7ea15a1cc8ccf39581e62f6b31583f

I am considering removing the ON (red) light, since the operator can identify the ON state from the rotary handle position, and the unit cannot be opened unless it is switched off.

Edit: this is not a modification. The pic in the post is for reference. The question is for a new panel (again aimed to cut cost)