Form-1 (Form of Separation) in Switchboards

Form of Separation is categorized into many types, w.r.t. partitions & cable termination. We have to better understand that each & every partition must comply with IP2x which is commonly denoted as Finger Touch Proof. Also, refer to the IEC Standard Guidelines.

In any form of separation, #partitions play the main role to achieve that level. These partitions can be made of metallic or non-metallic, but in the case of metallic, there should be an earth connection to make it #shockproof.

Form-1 of Separation is always achieved without any extra effort or we can say this is the form which is by default achieved whenever #Switchboard is manufactured. As there is no Separation and no need to cover any part from nearby functional units or we can say no barrier as well as Separation required in this Form-1.

Although the outer enclosure must be there to collaborate/ fix all parts on a single plate. Here we have to understand that in Form-1 all incoming, outgoing, busbar areas and cable termination areas don’t have any barriers or partitions in between, which means cable #terminations for incoming as well as outgoing, both are in the same chamber. (See Figure)

Form-1 is the common form of Separation where we need to lesser load capacity or small DBs (mainly wall-mounted DBs). Normally these DBs ratings are up to a maximum of 200-250A due to Cable Connection #capabilities. Although this rating/capacity is not manufactured in some countries (Like Korea, Japan etc.) they are utilizing it up to 630A, which are very stringent special applications.

There are major safety concerns with this Form-1, but the major part to play is the Size of the Switchboard, which means in this lower rating if we are going to achieve the next level of separation then each & every functional unit to be fixed in different-different #feeders which makes the bigger size of Switchboards.

As there is no separation/partitions so safety concern is bigger, so to minimize that below are do’s and don’t’s:-

DO’s:-

1. The enclosure must be achieved an IP2x Level of Ingress Protection.

2. There should be a proper gap between incoming and outgoing Terminals.

3. Top shrouding needs to fix on and above all functional units to prevent from direct touch.

4. Proper legends and markings must be provided for the identification of units and areas.

5. Ease of maintenance should be taken care of individual units on s single plates.

DON’T’s:-

1. Power connection & control connection must not be mixed in each other or not too closer to each other.

2. Incomer must not be mounted except than top most or bottom-most portion for better separation.

3. Don’t forget to isolate Busbar Connections properly to prevent direct intact.

4. Avoid direct touch of live connections in case of Metallic Shrouding.