Installation And Wiring
- Before installation and wiring, please ensure that professionals have read this manual.
- Before installation, please check the integrity of the ATS. Then turn on the ATS with the operating handle, check the flexibility of the operating mechanism, and check the on and off states of each phase and the load of the normal and alternative power sources.
- The nameplate of the product can be seen from the front. If you fail to install in the specified direction due to wiring or other reasons, please contact us. The safety distance S1, S2 should not be less than the distance specified in Figure 2. (More information on side picture).
- Check the control power supply voltage: 50 / 60Hz AC220V. The connecting wire of the control circuit should not be too long. The cross-sectional area of the copper wire should be greater than 2.0mm.
- Please equip the ATS with suitable circuit breakers according to the installation requirements of the power distribution system to ensure the safety of personnel and equipment.
Understanding Automatic Transfer Switch Basics – What is an Automatic Transfer Switch?
Advancements in technology have made life easier for mankind. All the technologies and devices created convert complex tasks into simple ones that require minimum human intervention. One such invention is an automatic transfer switch. If you are a business, you know the importance of a continuous power supply.
A few minutes of a power outage can lead to huge monetary losses. Businesses can’t afford a delay in power coming back on. This is why they need to install a backup generator and automatic transfer switch. An automatic transfer switch is a device that ensures a continuous supply of electrical power by switching from one power source to the other automatically.
You do not need an automatic transfer switch for your generator, but if you do not use one, it can complicate the entire process and cause delays in returning power. Automatic transfer switches make the whole process simpler, faster, and easier. Hospitals, data centers, offices, and other such facilities that have electrical equipment and require 24/7 electricity access need an alternative power source such as a generator that can supply electricity when the primary source is out.
How does an automatic transfer switch work?
An automatic transfer switch is an intelligent power switching device that is automatic, self-acting, and works by a controlled logic. The main purpose of an automatic transfer switch is to make sure that there is a continuous supply of utility power from the alternative power source when the primary source is not there.
Automated transfer switches are controlled by microprocessors that monitor the electrical parameters, such as the voltage of the primary and alternative power source. When access to the primary source is lost, the automated transfer switch automatically transfers the load circuits to the alternative power source or solar power source.
The majority of the automatic transfer switches has a primary connection to the primary source by default and will transfer to the alternative power source only when required or on operator command. The transfer sequence is as follows:
The transfer process can be automatic or manually done. When the primary power source is restored, the automatic transfer switch returns the load to the primary power source. This process may be self-acting or done manually.
What are the different types of arrangements available?
There are two different types of arrangements available those that utilize two power sources and those that utilize three power sources.
Two power sources
The standard transfer switch circuit includes an electrical utility and a generator or an alternative power supply. This circuit or system refers to an emergency standby generator system. It can consist of a single generator or multiple generators operating in parallel.
This type of system consists of two utility sources in the electrical panel. Access to two alternative power sources distributes the load and allows quick restoration of power and service. Both the power sources can work independently of each other. This requires the public utility company to provide dual electric services. They can also be generated from a single electric service that is distributed into multiple paths within the electrical circuit.
Transfer switches can be inserted between two generator sets for maximum power use. This is usually seen at remote installations where the generator is expected to supply electricity around the clock. In order to avoid putting stress on one generator, the power source is alternated between the two generators.
Critical facilities such as hospitals with an emergency standby generator system will include a second alternative power source or generator to serve as an emergency backup power source that may be used during long-term power outages due to extreme weather such as a snowstorm or when the first generator is undergoing maintenance. In these cases, the first generator may be permanently installed on-site, and the second generator is transferable and is deployed only when needed.
This unit consists of a double utility power supply along with an emergency standby generator. The generator can be accessed by a single transfer switch or by multiple transfer switches. If multiple transfer switches are involved, then a priority control scheme is out of place.
What are the different types of Automated transfer switch transition?
Automated transfer switches transition and transfer loads between normal and backup power sources with closed and open options. The type of load, its specific functions, and the safety of these functions are all important factors in determining what sort of transition is required.
1) Open transition
Open transition is a break-before-make transition. The automated transfer switch breaks the connection to the primary source before the transfer switch makes a connection with the other power source. There are further two types of open transition switches, including open in-phase and open-delayed.
2) Closed transition
A closed transition circuit consists of a make-before-break transfer. The automated transfer switch makes a connection to the secondary power source before breaking off its connection with the primary power source. This is no interval between the transfer of energy sources because of which downstream electrical appliances and loads receive continuous power.
What are the three modes of operation of an automated transfer switch?
The transfer from the primary electric source to an alternative backup energy source is performed manually by pushing a button. This has to be done locally.
This type of transfer switch also works manually and requires human intervention. The person has to press a button or rotate a switch to cause an electromechanical device to start up the switching mechanism. The initiation can be local or remote.
This type of transfer switch is self-acting and manages all operations by itself without any need for human intervention. It initiates the transfer process when the intelligent controller senses a loss of electrical power, when the power is restored, as shown by the indicator lights on the breaker panel.
What are the different types of switching mechanisms available?
The transfer switch consists of a switching mechanism that is responsible for carrying the current and shifting the load from one power source to the other. There are different types of switching mechanisms in a transfer switch.
The most economical and common type of switching mechanism if of the contractor type. Contractors are electrically-controlled switches in which a single operator opens a set of power contacts and closes the other set.
2) Molded case
This type of switching mechanism is used for closing and breaking a circuit between different contacts under normal and faulty conditions. They have a simple design and maybe mechanically operated, motor-operated, or over-center toggle.
3) Power frame
A power frame switch is large, fast, and way more powerful than the previously mentioned switching mechanisms. They can handle up to 6000 amps. It consists of a two-step stored energy tech that allows electrical and manual operation.
What are the different kinds of applications of ATSs, and how do they affect their structure?
1) Switched neutral
There are some three-phase power applications of ATS that need neutral conductors to be switched. In such systems, transfer switches are configured with a pole that performs identically to the individual power poles A B C. If it’s a single-phase application, a third pole can be created. A switched neutral ATS is used when the transfer is connected to more than one power source.
2) Bypass isolation
For the purpose of maintenance, bypass isolation automatic transfer switches can be used as they provide dual switching functions and redundancy. The other types of ATS are used for the daily transfer of electrical power from a secondary power source to the load.
At the same time, the bypass isolation switch serves as a backup device. It is usually used by hospitals and other critical facility centers as it allows ATS to be taken out and isolated from the main power source, which can then undergo maintenance, testing, and proper inspection.
3) Service entrance transfer switches
Offices and facilities that have a single utility source and a single emergency backup power source usually have an Automated transfer switch located at the entrance of the service to make sure that the critical load can be quickly shifted to the backup power without being interrupted.
In this system, non-critical loads are removed from the connection to the backup power so that there is no overload and the important downstream appliances get their power input.
Before selecting a transfer switch for your system, you should check the given WCR (Withstand current closing rating) to make sure the transfer switch is compatible and reliable. The rating is a great measure of the application flexibility of the transfer switch.
What kind of automated transfer switch should I buy?
Automatic transfer switches range between 50 to 400 amps. The type of automated transfer switch you should buy depends on what your load is.
1) Minimum load
Essential circuit switches, also known as load center transfer switches, are ideal for you if you want to power only your house’s basic devices and electrical appliances. These transfer switches can power up to 17 critical circuits from the main breaker panel. You just need to control the electrician who will wire the different circuits from the pane.
So you will have to pay the labor cost, which is higher as compared to other options. However, you won’t be powering all the appliances and outlets, which means that sockets that are not backed up with not power your appliances. So you will have to decide which sockets to connect to backup at the time of installation of the transfer switch.
2) Maximum load
The most simple option is to buy a service disconnect transfer switch that powers everything. It powers the complete breaker panel and provides backup for everything in your house. It is connected between the breaker panel and your electric meter. It has a load limit of 16 circuits and can take up many units of power. This kind of switch cost more but in the long term are of great benefit.
There is no wiring of different circuits required, so labor costs are way lesser as compared to labor-intensive transfer switches. If you want a backup for every item in your house, then you should definitely go with a service disconnect switch.
3) The only power a subpanel
A standard automatic transfer switch is created to power subpanels. They aren’t commonly used and may not be applicable in many areas. If you live in an area where you have a subpanel, then you can think about getting a standard automatic transfer switch. But you should contact your electrician first.
4) Split service power
If you need to power two breaker panels, then you should go for split service disconnect switches. If you have a 400 amp service with two 200 amp main breaker panels, then you should get two 200 amp service switches. Both of these transfer switches will be installed between the breaker panel and the electric meter.
5) Automatic transfer switch sizes
If you wish to use a service disconnect switch, then the amp must be equal to the amperage of the main breaker in your electrical panel. This means if you have a 300 amp main breaker, then you will need to buy a 300 amp automatic transfer switch.
On the other hand, load center transfer switches do not have to be sized according to the main breaker because they only have to power a few circuits. The amperage will depend upon how many appliances you wish to power.
6) Power distribution
The latest automatic transfer switches come with a great power management capacity which was not present in the transfer switches of the past. In the past, when transfer switch technology was relatively new, generators could not power multiple high-load appliances such as two heavy-duty air conditioning systems as the electrical demand was too high and caused an increased burden on the generator. But with advancements in technology, automatic transfer switches have been improved and now have the capacity to manage power properly.
This includes the concept of A/C shedding and power management modules. A/C shedding refers to turning off the air conditioner if the transfer switch senses a flaw in the generator and the generator can’t tolerate the increased load. On the other hand, the power management nodule can tolerate multiple loads by deciding which appliances or load is significant and which is not.
7) Generator compatibility
If you have brought a backup generator, then it is essential to buy a transfer switch. You should buy both of them at the same time. In the majority of cases, the automated transfer switch comes along with generators, but that is not always the case. You need to ensure that the switch is compatible with the generator and your power needs.
Why should you get an automated transfer switch for your business?
An automatic transfer switch offers many benefits to your business by increasing reliability and productivity. But that’s not all, here are a few advantages why you should invest in a transfer switch:
1) Continuous power
If there is a power outage, your business will not face any losses and can continue functioning. A generator can provide backup electrical energy to power your entire office, but without a transfer switch, you will have to manually switch from the primary energy source to the generator. This will be time-consuming and complex.
These automated switches provide safety and protection from possible hazards. Handling electrical sources can lead to electrical hazards. Employees may be hurt by manually handling the generator, especially when there is no light. An automated transfer switch automatically shifts the load from the main energy source to the alternative energy source without the need for human intervention. This removes all possible dangers associated with the manual handling of generators.
As mentioned above, once the automated transfer switch has been installed, restoring power is no longer a hassle. It will become a simple operation that you won’t even notice. You can power everything in your office by using an automatic transfer switch.
Transfer switches are a brilliant invention that has made our lives simpler and easier. Simply install an automatic transfer switch in your office and house with a generator and leave all the worries behind. You won’t even notice when the electricity goes out and comes back on! Perfection of this device will be your only complaint.