Year: 2026

What is the future of PV power?

Solar energy is today the fastest growing segment in renewable

energy and is believed to be one of the major energy sources in

the future.

Factors that vouch for a bright future of solar energy:

• Growing climate awareness brings more focus on renewable energy.

• Continuously higher legislative demands on increasing the share of green energy.

• Intense research and development of the PV technology in

order to make it more efficient and easier to produce.

Decreased production costs due to higher volumes and

improved production technique make it possible to pro-

duce low cost PV cells which in turn will expand the market.

Why is DC contactors needed?

PV plants contain some major application for DC swit

ching, since the electricity produced by the PV panels is DC.

Depending on application requirements, different products can

be used for switching. Contactors are typically selected for app

lications with the need for remote control and switching at least

once per day.

The GAF contactor’s ability to break DC up to 2000 A at a voltage

up to 1000 V derives from the use of permanent magnets in the

arc packages. The magnets enable the contactor to extinguish the

powerful electrical arcs that arise between the contact surfaces

when breaking DC. Normal AF contactors can break DC up to

some extent but since they lack the permanent magnets they

will not be able to break DC as a corresponding GAF contactor.

Applications – solar

What is PV power?

Photovoltaic (PV) power is a renewable energy source converting

sunlight directly into electrical energy using PV cells. Large PV

systems often consist of following main components:

• PV cells (combined to strings, generating the power).

•  Inverter (one or several, converting the generated DC voltage

into AC 50Hz or 60Hz, also including devices for switching,

protection and control).

•  Combiners (junction boxes, including switching devices, with

several cables on input and one cable on output).

• Trackers (mechanical structure to move the angle of PV cells

to follow the sun, increasing system efficiency, also including

motors, PLC, communication, protection).

• Switching devices and protection devices (to change PV

string configuration, protect from over currents, surge

voltages and earth faults etc.).

• Distribution transformer (transforming low voltage to high

voltage, as grid connection often is done on high voltage level).

Features and benefits

Powerful

•  1000 V DC switching ratings (IEC).

•  UL (508) rated up to 600 V DC.

Flexible

•  Wide control voltage range (e.g. 100-250 V AC/DC) means

less versions covering the entire range.

•  PLC interface with 24 V DC / 10 mA for GAF/AF400…2050.

•  Ideal for remote and fast operation.

Efficient

•  The AF electronic coil interface reduces power consumption

5-10 times at holding compared to conventional contactors.

Reliable

•  The GAF contactor is based on the well proven AF contactor.

•  Less sensitive to voltage drops due to a drop-out voltage

of 55% of the lower nominal value along with 20 ms sag

and dip immunity. These features avoid the problems with

contactor chattering and welding.

•  Elimination of contact bounce and chattering allows for

increased reliability and service life.

Quiet

•  DC powered coil makes the contactor virtually noise free.

Easy

•  The external dimensions of the GAF contactors are the same

as corresponding AF contactors making it easy to order and install.

•  Existing add on accessories for A/AF range of three pole

contactors will fit the GAF contactors.

The GAF contactor range

A compact and efficient way of DC switching

The new GAF range contactors are the latest addition to ABB’s

well established A/AF range. This further extends our offering  of

contactors for DC switching at voltages up to 1000 V DC. The

GAF contactors utilize all the well known features of the existing

A/AF range such as modern and compact design. In addition

all the benefits from the AF coil technology and reliability of a

proven contactor design. These contactors are rated for DC-1

or DC general purpose applications according to IEC 1000 V

DC or cULus 600 V DC. The new GAF contactors share the

external dimensions of its corresponding standard AF contactor.

ABB’ range of AF contactors is the industry benchmark. 

The integrated electronically controlled coil offers

multiple benefits over conventional alternatives, and together  with

ABB’s wide product offering an optimal configuration, every time.

AF1250 3-pole contactors are designed for switching power circuits up to 1260 A (AC-1) or 1210 A

UL/CSA

general use. Thanks to the AF technology, the contactors accept a wide control voltage range

(48…500 V 50/60 Hz and 24…500 V DC) with only 4 coils managing large control voltage variations,

reducing panel energy consumptions and ensuring distinct operations in unstable networks.

Furthermore, PLC control and surge protection is built-in, offering a compact solution. AF contactors

have a block type design, which can be easily extended with add-on auxiliary contact blocks and an

additional wide range of accessories.

Product conformity & compliance

REACH (Regulation EC 1907/2006)

AF contactors and related accessories were

classified as Articles and, during normal and

reasonably foreseeable conditions of use, do not

intentionally release any substance or preparation.

ABB continuously undertakes communications

throughout its supply chain in order to collect

information about suppliers’ compliance with

REACH regulation.

SVHC (Regulation EC 1907/2006 REACH)

ABB continuously assesses its products for content

of Substances of Very High Concern (SVHC), as

included in the “Candidate List” by the European

Chemicals Agency (ECHA). According to our best

knowledge, AF contactors and related accessories

do not contain SVHC substances exceeding

0.1 % w/w.

RoHS II

AF contactors and related accessories are within the

scope of Directive 2011/65/EU (RoHS II) and

Amendment 2015/863. starting from July 22 2019.

WEEE

The Waste Electrical and Electronic Equipment

Directive (WEEE Directive) is the European

community directive 2012/19/EU on waste electrical

and electronic equipment (WEEE) which, together

with the RoHS Directive, became European law in

February 2003.

Product safety

Compliance with essential health and safety

requirements has been assured by compliance with

the applicable product and safety standards.

The validation according to the product and safety

standards is carried out by third party tests

laboratory (STIEE / TL030) in respect of the EN ISO/

IEC 17025 European standard, according to IECEE CB

scheme. CB certificate has been issued.

Voltage sag immunity

The ability of equipment to withstand momentary

electrical power interruptions or sags.

Voltage sag

An rms reduction in the AC voltage, at the power

frequency, for durations from a half cycle to a few

seconds. The IEC terminology for this phenomenon

is voltage dip.

Characteristics

• AF09Z…AF38Z, AF40…AF750 contactors and NFZ

contactor relays are compliant to SEMI F47 (1)

and withstand voltage sags for :

– required voltage sag immunity 

– recommended voltage sag immunity (≤ 20 ms)

• Conditions of use: – rated control circuit voltages between 24 V to

500 V AC 50 / 60 Hz (see selection table)

– air ambient temperature -20°C ≤ Ɵ ≤ +60°C 

– 1-stack and factory-mounted 2-stack contactors

(2 stack contactors as AF..-30-11-.., AF..-30-22-..) 

– 1-stack and 2-stack contactor relays- no additional accessories.

(1) AF09Z…AF38Z and AF40…AF370 are compliant with SEMI

F47-0706. AF400…AF750 are compliant with SEMI F47-0200.

AF09Z … AF38Z and AF40 … AF750 contactors, NFZ contactor relays

increase the voltage sag immunity and the uptime of semiconductor

processing equipment without use of specific accessory.

Definitions according to SEMI F47 (1)

SEMIF47 defines the voltage sag immunity required for

semiconductor processing, metrology and automated

test equipment, and on subsystems and components

which are used in the construction of semiconductor

processing equipment including but not limited to:

• Power supplies

• Generators

• Robots and factory interface

• Chillers, pumps, blowers

• AC operated contactors and contactor relays

• …

Function

STOTZ selective main circuit breakers operate voltage-independent. They do not require

auxiliary energy for switching the device on or off or for their protection functionality.

A straight forward design ensures the reliable protection function. The functional elements

consist of proven electromechanical components specifically designed for these requirements.

For overload tripping, a thermostatic bimetal is used, as in the case of a standard circuit

breaker. And also as for circuit-breakers, it is necessary to separate main contacts quickly

by using a short-circuit “hammer trip” solenoid to ensure effective short-circuit limitation.

When the downstream protective device has tripped because of a short circuit, the contact

tips reclose again. This occurs without auxiliary voltage through a simple spring-type system.

If a short circuit occurs between the S 750 and the downstream mcb, another bimetal release

enables the short-time delay tripping. Both the selective release and the overload release

trip the mechanism and ensure that contact tips remain in the open position to comply with

isolation requirements.

The current is limited and the arc is quenched as in the case of circuit-breakers.

The underlying switching principle makes a special selectivity behaviour possible: current

limiting selectivity. When a short circuit occurs, the S 750 supports the downstream mcb

and also limits the energy that has an impact on the installation and – subsequently – on the

network of the supplier. The selectivity behaviour of the S 750 offers major advantages over

fuse-based technologies.

For these applications, selective main circuit breakers:

●  ensure load current carrying capability over a large temperature range;

●  protect cables in the case of functional overload;

●  protect cables in the case of a short circuit;

●  clear high short-circuit currents reliable;

●  limit the let-through current and let-through energy also in the case of selective short-circuit

disconnection by downstream mcb

●  provide disconnection and re-connection of installation, also by ordinary people;

●  provide selectivity with respect to downstream circuit-breakers and upstream fuses;

●  ensure highest availibility of electrical power supply for the customer.