IEC 61439 Panel / IEC 61439 Type Tested Panel / TTA Panel / Type Tested Assembly (TTA)

M.B. Automation are manufacturers & exporters of IEC 61439 Panel / IEC 61439 Type Tested Panel in India.

A low-voltage switchgear and controlgear assembly (ASSEMBLY) is a combination of low-voltage switching devices together with associated equipment (for controlling, measuring, signalling, etc.) complete with all the internal mechanical and electrical interconnections and structural parts. As with every component of an electrical installation, the ASSEMBLY also has to comply with its appropriate standard.

In January 2009 the IEC 61439, the new standard for lowvoltage switchgear and controlgear ASSEMBLIES, was published. This was the aim of an international project group which had been working on a task named "radical restructuring and revision of IEC 60439 series" since 1998. This initiative was introduced by several countries following dissatisfaction
with the IEC 60439 series. The purpose was to harmonise and define all general requirements for low-voltage electrical ASSEMBLIES.

The new IEC 61439 standard applies to enclosures for which the rated voltage is under 1000 V AC (at frequencies not exceeding 1000 Hz) or 1500 V DC. The standard defines the design verified ASSEMBLIES and eliminates completely the categories TTA and PTTA. In order to conform to the standard, type tests have been replaced by a design verification which can be carried out by the three following equivalent and alternative methods: testing, calculation/measurement or application of design rules.

The following parts are mentioned and do not have equal weighting. There is a formal hierarchy. Each part can not be used individually:
- IEC 61439-1 "General rules"
- IEC 61439-2 "Power switchgear and controlgear ASSEMBLIES"
- IEC 61439-3 "Distribution boards"
- IEC 61439-4 "ASSEMBLIES for construction sites"
- IEC 61439-5 "ASSEMBLIES for power distribution"
- IEC 61439-6 "Busbar trunking systems"

The IEC 61439 standard
All low-voltage switchgear and controlgear assemblies in the European Economic Area are required to comply with the IEC 61439 standard. The standard describes the design verification for controlgear assemblies and the responsibilities of the manufacturer and switchboard manufacturer.

Scope of the IEC 61439 standard
The IEC 61439 standard consists of several parts. The general part 1 applies to switchgear, power distribution boards and control cabinets, while part 2 applies to power switchgear and controlgear assemblies.

IEC 61439 'Low-voltage switchgear and control gear assemblies specifies standard arrangements of switchboard (call forms of internal separation). They are labelled as Form 1, Form 2, Form 3 and Form 4. Forms 2, 3 and 4 are further broken down into Form 2a, 2b, 3a, 3b, 4a and 4b. Each Form relates to the internal separation of the busbars, functional units and terminals, each being defined as:

Busbar -
low impedance conductor to which several electric circuits can be connected
Main busbar - busbar to which one or more distribution busbar, incoming unit or outgoing unit can be connected
Distribution busbar - busbar in one section which is connected to the main busbar from which incoming or outgoing units can be connecte

Functional Unit
- part of the assembly comprising the electrical and mechanical elements that contribute to the fulfilment of the same function
Incoming unit - a functional unit which feeds energy into the assembly
Outgoing unit - functional unit supplying power to the outgoing circuits

Terminals -
part of the assembly which provides for connection of incoming and outgoing cable and busbar
Internal separation is achieved by using barriers or partitions (including metallic or non-metallic), insulation of live parts or an integral housing (i.e. moulded case circuit breaker). The internal barriers should provide protection against contact with IP XXB and against the ingress of foreign bodies to at least IP 2X.

Form 1 has no internal separation between, while Form 4b has the greatest with busbars, functional units and terminals all being separated
Forms of separation from 1 - no internal separation of the busbars, functional units and terminals from each other.
Form 2a - separation of the busbars from the functional units. Terminals are not separated from the busbars.
Form 2b - as for 2a, but the terminals are not separated from the functional units.
Form 3a - separating the busbars from the functional units and each functional unit from the other units. The terminals of each functional unit are not separated from each other. Terminals are not separate from the busbars.
Form 3b - as per 3a, but with the terminals separated from the busbar (and functional units)
Form 4a - separation of the busbars from the functional units and each functional unit from the other units. Separation of the terminals for a functional unit from the busbars and those of any other unit. Terminals enclosed in the same compartment as the functional unit.
Form 4b - as per 4a, but with the terminals for each functional unit enclosed in their own space.

Features & Technical Specification:
- 100% Modular Structure; can be dispatched into a pack.
- Flexible Horizontal/ Vertical busbar and Cable Compartment Configuration.
- Compartmentalised - up to Form 4 IP 54 with a polyurethane foam gasket.
- Doors are available in heights of 200mm & multiplies of 100mm.
- Horizontal Busbar chambers, Vertical cable chambers are provided with Individual bolted cove Rear bolted covers.
- Plinth (modular) & Side cover (Optional.)
- Wide Variety of Standard MCC ranges.
- Additional accessories like Cable support, Busbar Support and Baying kit are available.
- Double front execution can also be provided.
- Lifting Channel provided as standard (instead of Eye-bolts) for higher load-carrying capacity.
- Bus Bar chamber (Top/ Bot) and Feeder doors (Left/ Right) are interchangeable.
- Doors are openable with hinges for 120-degree opening and Metal locks.
- The panel can be expanded in all 3 dimensions and bayed together using Baying Kit.
- All corner bars and crossbars can be placed at25mm intervals horizontal, vertical, and longitudinal.
- Horizontal & vertical separation plates are provided between all feeder compartments.
- Colours: RAL-7035 (structure finish) for structure, covers & doors.
- RAL-2000 (smooth finish) for Mtg. Plate, RAL-9000 (smooth finish) for Plinth and lifting channel.
- Sheet thickness 2.0mm GPSP for Structure, 2.0mm CRCA for mtg plate & mtg rail, 1.6mm CRCA for Covers & Doors, 1.2mm CRCA for Separation Plates.