Relay type from most manufacturers around the world
In this section you can find all the manufacturers and brands of relays that currently offer the best and largest offer of relays available in the market.
You can select the reference of the relays type you need and find its equivalence in other brands.
When choosing a relay among the different types of relays available in the market, you should always keep in mind the points that we present below.
First, replacement by failure of a relay that is already installed.
- Safety must always be the first step, so you have to make sure that the cabinet or machine to be handled is not in tension and that during the entire time that the manipulation lasts, the tension will not be reintegrated. accidental
- Check the size and model of the relay if it is visible to the naked eye
- Check if the relay is connected to a connection base to which the inputs and outputs are wired, or if there are terminals or Faston type pins on the relay itself. (In this case you must proceed to disconnect the cables to replace the relay)
- Verify (when the relays are pluggables) the type of pins through which the relay is connected to the base. These can be flat Faston type 2.8 of 4.5 or 6.2 mm wide, tubular as the old vacuum valves, 8 or 11 tubes (relay octal or rele undecal) or pin type.
- Check the number of terminal pins that the relay has. The number of pins is always related to the number of contacts the relay has. If the relay has inverter contacts, it will have 3 pins for each group of contacts, one for the normally closed contact, another for the inverter contact and a third for the normally open contact. If the relay has open contacts, it will have 2 pins for each group of contacts, one for the inverter contact and another for the normally open contact. To the total number it is necessary to add two more pins to connect to both ends of the relay coil. The most common inverter relay contacts carry 5, 8, 11, or 14 pins for relays of 1, 2, 3 or 4 groups of contacts respectively.
- Verify the numbering and disposition of the pins of the terminals that the relay has. Most manufacturers market relays that are completely interchangeable with those of other manufacturers and plug-in bases of another brand. It is very important to check the numbering recorded in the lower part of the relay for each group of contacts so that it is identical to the relay that will be replaced.
- Check the intensity or maximum power range of the relay to be replaced. The most common industrial relays can switch alternating currents of 5, 10, 16, and 30 amps at voltages of 250 or 380 volts.
- Check the voltage at which the relay coil works. It is the tension that we must maintain between the coil pins for the relay to act and are usually named with the numbers 1 and 2, or A1 (+) and A2 (-) when the coil works in direct current. In this case it is necessary to pay attention to the polarity indicated so as not to connect the terminals with the inverted polarity.
Second, choosing a relay for a new project
When we need to choose a relay type for a new application that we are designing, the factors that we must take into account to find the most suitable solution are very numerous, both technical and economic. Then we will list, without intending to be exhaustive, the most important points that must be taken into account.
- Verify the maximum switching capacity that we need in amps and the voltage in volts to which the load of the circuit we want to control with the relay will be connected. It is important to verify the minimum intensity and voltage, when we want to switch extremely small intensities, of only a few milli amperes, to make sure that the contacts of the chosen relay types can continue in these conditions.
- Check the type of load with which the relay will work. It is very different if the load is a resistance, a squirrel cage electric motor, an electro valve, the coil of a very large contactor, a fluorescent lamp, a led bulb, etc., because each type of load “reacts” differently when connected and disconnected.
- Verify the number of operations per second, per minute, per hour, per month or per year that the relay will carry out, to make a forecast of its useful life at nominal load and the estimated time for its replacement by a new relay, taking into account that the most usual electromechanical relays are usually designed for 100,000 to 200,000 operations in their nominal switching conditions for pure resistive load (cosΦ = 1). At this point it is usually interesting to study the use of a solid-state relay (designed for more than 10,000,000 operations) instead of an electromechanical relays if we only need open contacts.
- Check the available space in the control cabinet that we are designing to choose more compact relay models for each group of contacts or if we have enough space for larger relay models, with greater switching capacity, more durable, and easier to replace or replace by other brands by maintenance personnel.
- Check the quantity of relays that we are going to have in the DIN Rail of the control cabinet and take into account the unit consumption of the coil of each relay in watts or (VA if it is a coil intended to work in alternating current), to size the power of the necessary power supply or to choose between the relay types that can work with coils fed directly to the mains voltage. The most common coil voltages are, in direct current 6, 12, 24, 48, 60, 115, 220 and in alternating current 6, 12, 24, 45, 60, 120, 230 volts
- Check the number of relays inside the cabinet and the power switched by them, to study the evacuation of the heat generated inside the control cabinet envelope, so that they do not exceed the maximum temperature values that are usually around 60 – 70 ° C maximum
- Check the permissible noise and / or vibration level to choose the least noisy relay types or even install relays that do not produce any noise in your operation, such as solid state relays.
- Check the level of dust, vibration or humidity present in the work area where the control cabinet that will house the relays will be located, to choose hermetic relays or electronic relays that are insensitive to these problems.
In any case, it is a good habit in the process of designing a new installation to consult the manufacturer or distributor about the most suitable types of relays for each application and to be advised by experts to prevent very simple errors to be solved in the initial phase of the project .