The use of one static switch per module is favoured to avoid a single point of failure.
Static switch circuit diagram.
Static transfer switch b.
A transfer switch is an electrical switch that switches a load between two sources.
In some ups installations the transfer is delayed for a finite time to allow a load protection fuse or circuit breaker to act and clear the fault so avoiding subjecting the load to raw mains or even.
Some transfer switches are manual in that an operator effects the transfer by throwing a switch while others are automatic and trigger when they sense one of the sources has lost or gained power.
Today s upss that use modular technology are flexible and easily scalable while protecting their critical load from many different threat types.
Sts 4p 100 400 600 a static switch is fitted with a block diagram with led indicators and a 4 line 20char display.
When a deviation from the pre set limits on the preferred source is detected a transfer signal is generated.
The circuit operation occurs when switch s 1 is closed since the triac q 1 will initially be in the block ing condition.
A ups bypass switch is a non essential addition to an uninterruptible power supply system that while not integral to ups operation is definitely useful in the event of maintenance or repair.
Static switches play a key role in assuring this resilient performance.
The block diagram of a static switch is shown below.
An online system can also use the static switch to transfer the load to bypass if an overload condition drawing excessive current develops.
Control system and metering system.
Three wire cable runs between the switches and the outlet.
The core items you need in order to be protected in the event of power failure are a ups and a battery to supply the power under standard operation this should be all that is required.
The above thyristor firing circuit is similar in design to the dc scr circuit except for the omission of an additional off switch and the inclusion of diode d 1 which prevents reverse bias being applied to the gate.
Control circuit of the sts the control circuit figure 2a takes as input the voltage magnitudes of the two feeders and performs a load transfer when needed.
A static power transfer switch consists of three basic parts.
Typical static switch circuit.
3 way switched outlet wiring.
A breaker or a bus assembly.
Together with the power source priority selection button enables operators to make full use of the apparatus.
Silicon controlled rectifiers of which the internal structure is made up of.
When this current reaches.
This circuit is wired the same way as the 3 way lights at this link.
Current flow will be through load r l s 1 r 1 and gate to mt1 junction of the thyristor.
The source is at the sw1 where the hot is connected to.
In this diagram two 3 way switches control a wall receptacle outlet that may be used to control a lamp from two entrances to a room.
