Form 4b Panel – The Ultimate Guide

Forms of segregation serve a big role in the designs of electrical switchboard. They provide shielding against touching live parts found in adjacent functional units.

You will determine the form panel type based on the protection needed, skill of those involved, and needed degree of maintainability.

Components Of Form 4b Panel

Form 4b panels helps in the segregation of terminals, busbars and functional units, with each being describe as:

• Busbar refer to low impedance conductor that you can connect several electric circuitries.

1. Main Busbar refers to busbar where you can attach one or extra distribution busbar, outgoing unit or incoming unit.
2. Distribution Busbar is found in one compartment that is linked to primary busbar from where you can connect outgoing or incoming units.

• Functional Unit is the assembly part consisting of the mechanical and electrical components that help in the achievement of similar role.

1. Incoming unit refers to the functional unit that supplies power into the form 4b panel assembly.
2. Outgoing unit is the functional unit that delivers power to the exiting circuitries.

• Terminals provide for coupling of busbar and incoming and exiting cable.

The form 4b panel needs to offer protection against entry of foreign substances to no less than IP2X and contact to IPXXB.

Components of Forms of Segregation

Difference Between Form 4a Panel And Form 4b Panel

Form 4 is the topmost rating of forms of separation. Busbars are separated from the external cabling terminals and functional units.

Moreover, the functional units are isolated from each other.

There are 2 main categories of form 4 panel comprising of:

Form 4a

In this form of segregation, the external cabling terminals are in similar section as the corresponding functional unit.

However, they are separated from terminals of other functional units.

You can attain busbar segregation using coating, wrapping or insulated coverings sleeving.

Form 4a Separation

Form 4b

With form 4b panel, the external cabling terminals are not in one section as the corresponding functional unit.

Busbars, terminals and functional units are all completed isolated from each other.

Just as in form 4a panel, you achieve busbar segregation by using coating, wrapping, or insulated coverings sleeving.

Form 4b Panel Segregation

Types Of Form 4b Panel

All Form 4b panels need termination of all related external conductors, neutral and both line(s) inside a compartment.

You will not find these external cabling terminals in the same compartment as the linked functional unit. Also, they are isolated from the other functional units’ terminals.

The different types of Form 4b Panels include:

Form 4b Type 4

Here, the segregation of busbars is attained through insulated coverings, and it requires isolation of;

1. Busbars away from the functional units.
2. Functional Units from one another.

• External cabling terminals from their functional unit, busbars and other group of terminals.

All the other types of forms of segregation are similar to Form 4b type 4, the main difference is on the method of separation.

Form 4b Type 4, 5 and 6

Type 5 needs busbar segregation using barriers and partitions with exiting terminals isolated by insulated coverings.

Type 6 requires separation of terminals and busbars using barriers and partitions.

Type 7 needs provision of independent, integrated cable glanding facilities for every circuitry. The isolation of extended terminals and busbars is achieved through barriers and partitions.

Form 4b Type 7 Panel

Advantages Of Using Form 4b Panel

The key function of form 4b panel is to safeguard the operator or installer from any electrical hazard.

This form of separation enables safe access for operator by guarantee the following:

• Protection against touching with live parts belonging to the adjoining functional units. The protection degree should be no less than IPXXB.
• Shielding from solid foreign substances being moved from one assembly unit to the nearby unit. The protection degree needs to be no less than IP2X.
• Reduced risk of causing or spreading an internal arc.

Form 4b Type 6 (Group Mounted) Vs. Form 4b Type 6 (Compartmentalized)

Form 4b Type 6 (Compartmentalized)

This type of form 4b panel needs segregation of:

• Busbars away from functional units
• Functional Units from one another
• Terminals for external wiring from the busbars and other terminals.

The diagram below a typical compartmentalized form 4b type 6 panel.

Form 4b Type 6 (Compartmentalized) Panel

Form 4b Type 6 (Group Mounted)

With group mounted form 4b type 6 panel, you use the integral device housing as the mechanism of isolation.

The separation is attained as follows:

1. Busbars segregation by rigid barrier
2. Functional units isolation from one another utilizing the integral housing.
3. External terminals isolated from one another and related functional units.

Form 4b Type 6 (Group Mounted) Panel

When To Use Form 4b Panel

You should use form 4b separation panel where it is essential to give protection from interior live components. Moreover, in applications where malfunction of functional units you are feeding from similar busbar would result in unacceptable disruption.

This this form of separation isolates all the terminations, you can segregate and operate on one functional unit.

Form 4b Panel Construction

To attain form 4b rating, you can use non-metallic or metallic physical barriers for isolation between busbars, terminals, and functional units.

Nonetheless, you can as well employ alternative techniques, which are simpler and highly affordable, to achieve isolation:

Integral Housing

When a functional unit housing has an IP2X degree of protection, you may use to offer internal isolation between functional units.

However, this method of separation does not apply for busbars.

The technique is applicable to Form 4b panel since it involves separating functional units from one another. This method is denoted by suffix “h” to the Form panel rating, for instance, Form 4bh.

Insulation On Terminals Or Busbars

Equally, you can use insulation method to isolate busbars from terminals and/or functional units.

Besides, it is possible to shroud terminals to offer separation from other functional units’ terminals.

In this method of segregation, you use suffix “i” to denote it, for example, Form 4bi panel.

Combination Of Insulation And Housing

Furthermore, it is possible to blend component housings and insulation to give internal segregation.

When you apply both techniques, you denote it by adding both suffixes ‘I’ and ‘h’, for example, Form 4bih.

For all your questions or inquiry on electrical enclosure panels, contact KDMSteel now.