Relay application Guide

Connector application Guide

PRODUCT SELECTION GUIDE

In order to help you select relay correctly, we offer a product selection flow to refer to.

METHOD 1（EMPHASISE ON LOAD CAPACITY）

1）Open the quick selection product catalog（arrange in load capacity sequence）.

2）Select several products according to contact load and contact style preliminary.

3）Rid of the product that doesn’t accord to the shell dimension. 

4）Rid of the product that doesn’t accord to the environment temperature and vibration character.

Open relevant product details according to the page of the catalog and make a choice after comparing. 

Please fill in the order according to the order mark and the quality grade of the product you selected．

METHOD 1（EMPHASISE ON SERIES）

1） 　Open the quick selection product catalog（arrange in series sequence）.

2）　Select several products according to the shell dimension preliminary.

3）  Rid of the product that doesn’t accord to the contact load and contact style.

4）  According to method 1 item 4 and item 5.

 CLASSIFICATION

The relay our company R&D mainly covers:

Electromagnetic relay：

A monstabillity relay，the output reverses to initial state after the stimulation of the coil retreated.

Latching relay：A double constable relay，the output retains former state after the stimulation of the coil retreated.

Thermostat：A temperature sense component，whose output is controlled by the temperature.

CONTACT STYLE 

TERMS and TEST

1 ELECTROMAGNETIC RELAY

1.1 TERMS

a)  Stimulation：control the input variable of relay，such as electrifying, heating and acceleration and so on. 

b)  High level: rating level, loading capacity exceed 28V，100mA. 

c) Low level: loading capacity between50mV, 10μA and 16V., 0mA. 

1.2 TEST

1.2.1 TEST PROCEDURE OF OPERATE VALUE, HOLDING VALUE AND RELEASE VALUE

Test procedure refers to figure 1.According to national military standard both figure 1a and figure 1b are correct. 

2 LATCHING RELAYS

2.1 OPERATING VALUE TEST

Testing of operating value（ without release value） can refer to figure 1a as the shading voltage test. Similarly it also can be tested as figure 2 step function voltage test. Firstly, give the coil 1 （later stimulation coil）stimulation and the outputs ought to accord to the circuit diagram. The operating voltages named self retain voltage. Oppositely, give the coil 2 stimulation and the operate voltage of coil 2 named reversion value.

3 THERMOSTATS

3.1 TERMS

3.1.1 TEMPERATURE CHARACTER

a）Operating temperature: The temperature value that the output of relay changes with the temperature ascends.

b）Nominal operating temperature: Nominal value of operate temperature, for example 50℃±3℃, 50℃ is nominal operating temperature.

c）Operating temperature deviation: Measured difference value between operating temperature and nominal operating temperature， for example 50℃±3℃, ±3℃is operating temperature deviation.

d）Reversion temperature: The temperature value that the output changes after the relay acts according to item a.

e）Temperature range: difference value between operating temperature and reversion temperature.

3.2 TEST

There are three test methods, and the three test methods are all regarded availability.

a) Measuring block test: At the room temperature, place the induce side of temperature of relay

close to the measuring block（mostly copper block） and no gap, through test measuring block temperature characters ascertain the temperature character of the relay.

b）Air circle test: place the relay in oven that having air circle circulation

 c)  Liquid test: place the relay in container that having liquid circulation.　

The test results of the three methods are different，often the difference between air circle test and liquid test is less，compared to measuring block test the difference is possibly 3℃～5℃。Measuring block test and air circle test are adopted usually. Otherwise temperature variety speed has great influence on test. Temperature variety speed must be controlled rigidly. To assure application requirement, the user and the supplier should communicate and amend.　

ENVIRONMENT TEMPERATURE

Environment temperature is not the room temperature but the temperature where the relay mounted. Environment temperature includes the balance on radiation of component around and radiation condition.

2 　 LOAD SWITCHING ABILITY

Load-carrying ability of relay is not always from low level to high level，the relay having no low level parameter cannot be used in low level.

Increasing the load voltage means decreasing load circuit, which can refer to load character.

3 　 LOAD CHARACTER

Contact load and life of the relay are operating frequency when the load serves as resistance under rating voltage current. When the load character change, the contact parameter will change accordingly, users can convert load current referring to table 3. 

TABLE 3 LOAD CURRENT CONVERSION of DIFFERENT LOAD CHARACTER

　　We suggest increasing contact protection measure for inductance load and electromechanical load, which can connect series .resistance-capacitance component parallel The selection of resistance can according to 0.5Ω/V to 1Ω/V every volt and the selection of capacitance can according to 1μf / V. Also it can connect diode or restrain diode parallel.

It would need resistance in series if capacitance serves for load. Otherwise it will bring fatal damages to relay contacts.

4 TRANSIENT STATE RESTRAIN

It will produce several fold negative peak voltage when remove the stimulation voltage of the coil, which will bring great damage to the circuit. And it should be restrained. There are many restrain methods. Commonly connecting diode parallel is most simple and economy. But connecting diode will prolong release period.

Manufacturer also supplies relay having transient state restrain function. It is more convenient. These kinds of coils have polarity. Pay more attention in application. Polarity connect in reverse can damage restrain component and lead the relay to invalidation. When testing the insulation resistance and voltage withstand of these kinds of relays the coil should short circuit, avoiding mangle the restrain components.

5  COIL STIMULATION SELECTION

Stimulation voltage selection of relay should according to rating, because relay circumstance, mechanics and electricity capability are tested under that condition. If the coil operate voltage act as stimulation voltage, it will bring fatal damage to the relay.

Voltage pulse width of the latching relay coil should satisfy the requirement（treble the operate time ），but electrifying perennial is unsuitable，and no more than 15 minute. Because electrifying perennial will make the coil hot and damaged.

6  CONTACT PARALLEL

Contact parallel cannot improve the current load ability, because every contact team operate is not always synchronization, which lead the contact to act earlier undertake whole current. But Contact parallel can improve the reliability of connectedness of relay.

7  SEAL CHARACTER

Seal character has great influence on relay application and storage. Good seal character is favorable for relays working under high sea level. Welding product instead of tin embedding product is a advisable.

8  THERMOSTAT TEMPERATURE CHARACTER SELECTION

The temperature character of thermostat is relative to environment, equipment, parameter and so on. It is important to retain consistent with the locale condition. It would require further certificate whether the eligibility product applicable or not. Commonly, you can select an appropriate temperature character value and find out the difference through application. Then correspond with supplier and amend.

9  DERATED CAPACITY IN SERVICE

Appropriate derated capacity in service can decrease the invalidation probability of relay under the rating circuit and increase the life and reliability of the relay. Advice derated capacity in service at 70 percent of the rating. 

APPLICATION AND MOUNTING

1  The down lead of sealed relay is glass insulated, and cannot be shaken random. Otherwise the glass insulated is easily broken. Thereby the relay seal ability is damaged or leads the down lead to flexible, rupture or makes the relay invalidation. When need pull the down lead, please fix the down lead 3-millimeter close up the motherboard, and the biggish diameter down lead shouldn’t be shaken. 

2 Twisting the lead with apropos force when welding lead，avoiding the down lead become flexible. The down lead is easily damaged under the condition of bonding long, weight and hard lead. After completing the mounting, fix the long lead, and avoid damaging the down lead because of the lead swing. 

3 The relay has a varnish-coated layer, if the relay cover requires grounding, please rid the vanish of bond point. Wedding period should be very rapid or adopt cooling protection. 

4 The solder of leading of the relay should select neuter solder, avoiding contaminating glass insulator and reducing insurability. At the same time long wedding period is not suitable. The wedding temperature is no more than 260 ℃. Therefore you can select matching electric iron referring to the wedding temperature. Moreover wedding period persistence no more than 3 seconds. Repeat welding after the welding point cooling down if require. Clear the solder in time. 

5 If the relay falls to the ground inadvertent, the inner component of the relay is possible injured because of the intensity impact. Checkout the relay is eligible. 

6 The relay should not support the product itself if the relay directly mounted on printed circuit board. The down lead, relay cover and printed circuit board should be embedded Integrative. Possibly select the relay with installation lug or add sleeve in addition, avoiding endanger the safety of down lead or product. 

7 When mount the relays avoiding synchronic cantilever beam, for fear of transfer energy to relay leading the relay to under syntonic. Especially printed circuit board is easily syntonic and lead the relay to invalidation if the rigidity of printed circuit board is not enough, therefore the rigidity of printed circuit boards should be strengthen. 

8 Relay color mark: Commonly, the color of glass insulator of one coil down lead of electromagnetic relay is different from others. For latching relay, transient state restrains relay and counterbalance relay it expresses the stimulation positive pole .For latching relay，it also expresses the positive pole down lead. Attentively, avoid making you circuit confusion. For electromagnetic relay it is only a down lead mark and no polarity requirement. 

9 To ensure reliable heat transfer the induce side of temperature of thermostat mounted close to the control unit, and no gap, 

7 ORDER

　　Once make a choice of relay, please fill in order contract refer to the order mark.

8 STORAGE