Songchuan-Technical-Infomation-html.html

SONG CHUAN

Technical Information

▓

INTRODUCTION

The technical Information is divided into four basic parts:
(1) General application guidelines.
(2) Guidelines for relay handling.
(3) Guidelines for selecting contact protection circuits.
(4) Guidelines for selecting a temperature tolerant relay
for your application.

In addition to the technical information, all data sheets in
this catalog also include notes relevant to each specific
relay. Please refer to these relay-specific notes, as they
contain information vital to optimum relay performance.

▓

GENERAL APPLICATION

1. Avoid Abuse

As with any electro-mechanical device, relays are
sensitive to abuse. To assure optimum performance,
avoid dropping, hitting, or other unnecessary shocks to
the relay.

2. Never Remove the Case

The case of a relay is an integral part of that relay.
SONG CHUAN relays are not designed to have the case
detached. Never remove the case, as specifications or
performance cannot be guaranteed.

3. Atmosphere Considerations

SONG CHUAN recommends that you use unsealed
relays in an atmosphere with only a minimum of dust and
other contaminants. If a relay must withstand a harsh
atmosphere, SONG CHUAN recommends that you utilize
a sealed relay.

4. Warning--Silicon Based Resins

Some silicon based resins can cause contact failure in a
relay. The silicon based resin does not need to come in
direct contact to cause damage

—

it just needs to be in

close proximity. In cases where silicon based resins are
used, it is recommended that a sealed relay be used.

5. Voltage

To assure meeting to electrical and performance
characte ristics, only the correct rated voltage should be
applied to the coil, i.e., voltage sine waves only for AC
coils, rectangular for DC coils.

6. Over Voltage

Although typically a spike will not effect a relay's
performance, the voltage on the coil should not
continuously exceed the maximum allowable voltage.

7. Contact Current

Currents that exceed the designated values should be
avoided.

8. Check Your Load and Conditions

The specifications provided in this catalog are "typical"
specifications and are given only as guidelines. The
performance of contacts vary depending on both the type
of load and operating conditions encountered. Please
consider your specific load and operating conditions in
selecting the optimum relay for your application.

9. Warning--Ambient Temperature

The ambient temperature ranges, listed in the general
specifications for each relay, must be adhered to, to
assure proper operation. Note: Both the storage and
operating range differs for the sensitive and standard
version of the same model. Refer to the data sheet of the
relay for specific information.

10. Ultrasonic Cleaning

Never use any type of ultrasonic cleaning. Ultrasonic
cleaning is always traumatic and is not recommended.

11. Pickup & Dropout Voltages

Both pickup and dropout voltages should be considered
when selecting a relay coil voltage. For specific
information, contact us.

12. Relay Coil Transient Suppression

The use of a single diode in parallel with the coil for
transient suppression causes longer contact release time.
On power relays, longer release time may reduce relay
life. For longer contact life, use a zener and diode,
a capacitor and resistor, or only a resistor.

13. Storage

Avoid storing relays in excessively humid conditions
where possible, as moisture can affect performance
in some cases.

Technical Information

SONG CHUAN

Technical Information

14. Usage Ambient Condition

(1) Temperature: The allowable temperature range
differs with each relay.
Transporting and storing relays in a tube package,
the temperature may differ from the allowable
range of the relay. So, please contact us for
individual specifications.
(2) Humidity: 5 to 85% R.H.
(3) Pressure: 86 to 106 kPa

Furthermore, the humidity range varies with
the temperature. So, use relays within the
range indicated in the graph below.

(4) Please pay attention to the phenomenon of freezing
in the low temperature environment below 0°C.
Icing refers to the phenomenon of condensation of
water on the relay when the temperature reaches
below freezing point in the condensation and
abnormally high humidity environment. Freezing may
cause partial adhesion, delayed action, or icing
between contacts and lead to contact conduction
failure. Please evaluate the actual use of
the environment.

▓

RELAY HANDLING

SONG CHUAN utilizes extensive quality control
measures, and takes extreme care in packaging
to assure that the relays you receive are in the
best possible operating condition. Once they enter
your facility, some common sense care can
prevent damage during handling.
Some areas to closely monitor and supervise include:

1. Handling

◆

Avoid handling relay terminals.

Oils and contaminates common to the human hand can
cause contamination of the surface finish--which in turn
can lead to solder ability problems.

◆

Always store relays at recommended

temperatures.

Observe maximum storage temperatures listed in the
general specifications section of the data sheet
for yourspecific relay.

◆

Avoid misalignment of the terminal layout

and PC board hole pattern.

Even if there is just a slight misalignment, forcing a relay
into the board can cause relay damage compromising
such important factors as seal integrity, relay
performance, and relay reliability.

◆

Store handle relays in a clean environment.

Your relays are state-of-the-art, electromechanical
components, and should be stored and handled as such.
Even environmentally sealed relays have exposed
contacts that are subject to contamination, and therefore
are minimally sensitive to their storage and production
environment.

2. Mounting

◆

Suggested PC board layout.

Refer to the PC board layout located on the data sheet
for your specific relay.

◆

For automatic insertion.

SONG CHUAN relays are available packaged for a
variety of automatic insertion machines. Please consult
with our Technical Services Department.

◆

Never bend terminals.

Once relay terminals are bent, performance can no
longer be guaranteed. Never bend terminals to
make them self-clinching, and avoid bending them to
fit misaligned holes.

◆

Connection and mounting.

To connect a lead wire to the terminal or to mount the
relay on a PC board, securely wind the lead wire around
the terminal as shown.

Incorrect

Bending the relay leads, for

any reason, can cause failure.

Correct

Relay terminals remain straight

and penetrate completely

through the PC board.

Correct

lncorrect

(The allowable temperature range differs for each relay.)

Tolerance range

Humidity, %RH

(Avoid

freezing when

used at

temperatures

lower than

0°C)

(Avoid

condensation

when used at

temperatures

higher than 0°C )

Temperature, °C

SONG CHUAN

Technical Information

3. Soldering and washing guidelines

◆

Flux coating

●

Adjust the position of the PC board

so that flux does not overflow onto

the top of it.

●

Use rosin-based flux, which is non-

corrosive and requires no washing.

●

Do not use Automatic Flux Coating

Method to dust-cover type relays.

●

Do not overflow onto the top of PC

board, in such a case, the flux may

even penetrate a flux-resistant

type relay.

◆

Preheating

●

Be sure to preheat before soldering.

●

Preheating acts to improve solder

ability.

●

Preheat according to the following

conditions:

Temperature--100

℃

/212

℉

or less

Time within--approx. 1 minute

◆

Soldering

Automatic Soldering

●

Flow solder is the optimum method

for soldering.

●

Adjust the level of solder so that it

does not overflow onto the top of

the PC board.

●

Unless otherwise specified, solder

under the following conditions

depending on the type of relay.

●

Solder Temperature---approx.

250

℃

/482

℉

for SnPb soldering,

260

℃

/500

℉

for Lead-free oldering.

●

Soldering Time---within approx. 5

seconds

●

Solder Ratio--- Sn/Pb = 60/40 or

63/37

Hand Soldering

●

Keep the tip of the soldering iron

clean.

●

Solder Iron---30W to 60W.

●

Iron Tip Temperature--approx.

300

℃

/572

℉

●

Solder Time---within approx. 3

seconds

◆

Cooling

●

Immediate air cooling is

recommended to prevent

deterioration of the relay and

surrounding parts due to soldering

heat.

●

Although the sealed type relay can

be cleaned, avoid immersing the

relay into cold liquid (such as

washing solvent) immediately after

soldering. Doing so may eteriorate

the sealing performance.

◆

Washing

●

Do not wash flux-resistant type

relays and dust cover type relays

by immersion.

●

Careless washing may cause

washing solvent to penetrate the

relay.

●

Plastic sealed type relays can be

washed by immersion. Use

washing solvents shown in Table 1.

●

Use of other washing solvents may

damage the relay case and cover,

and also cause washing solvent to

penetrate the relay.

●

Washing with the boiling methods

is recommended. Avoid ultrasonic

washing on relays. Use of ultra-

sonic cleaning may cause breaks

in the coil or slight sticking of

contacts due to the ultrasonic

energy.

Table 1. Washing solvent compatibility chart for sealed

type relays.

◆

Coating

●

If the PC board is to be coated to

prevent the insulation of the PC

board from deteriorating due to

corrosive gases and high

temperature, note the following.

Heater

Foamed flux

Solder

Washing solvent

Flourinated

Aqueous

Chlorinated

Alcoholic

Freon TF

Aqua flux

Perclean B-5

IPA

Freon TE

#WL 1000

Perclean D

Ethanol

Freon TES

Indusco 624

Cholorothene VG

Freon TMC

Indusco1000

Cholorothene N

Alpha 1001

Lonco terge 530

Cholorosolve

Alpha 1003

Hollis 310

Alpha 564

Solvent

trade

name

Lonco Terg

Trichcloroethan

Technical Information

SONG CHUAN

Technical Information

●

Do not coat dust-cover type relays

and flux-resistant type relays.

●

Depending on the type, some

coating materials may have an

adverse affect on relays, select

coating materials carefully.

●

Not to use silicon based resins.

4.Surface Mounting

◆

Cream solder printing

●

Please use the cream solder that

contains a flux without a large of

chlorine, to avoid the terminal

being corroded.

◆

Mounting

●

The holding pressure on relay

must be equal or less than the

following reference. Or we can’t

guarantee the relay performance.

Direction A: 1.96N max.

Direction B: 4.9N max.

Direction C: 1.96N max

◆

Reflow soldering

●

Recommended conditions of

soldering for example, as

following. (The temperature profile

shows the temperature on the PC

board side.)

●

Don’t make the relay in a cold

washing solvent instantly after

soldering, to avoid the seal ability

of relay being damaged.

(1) IRS method (for SnPb solder)

(2) IRS method (for Pb-Free solder)

(3) VPS method

◆

Washing

●

Washing by boiling method and

immersion is recommended.

●

Use of ultra-sonic cleaning may

cause break in the coil or slight

sticking of contacts.

●

Recommended washing solvent

are aqueous solvent & alcoholic

solvent. Furthermore, the solvent

temperature must be within 40

℃

Washing solvent

▓

CONTACT PROTECTION

CIRCUIT

A contact protection circuit, designed to prolong the life

expectancy of the relay is recommended. This protection

will have the additional advantage of suppressing noise,

as well as preventing the generation of carbon at the

contact surface when the relay contact is opened.

However, unless designed correctly, the protection circuit

may produce adverse effects, such as prolonging the

release time of the load. The following table lists

examples of contact protection circuits:

DIODE AND ZENER DIODE CIRCUIT

●

DC applications only.

●

Utilize when diode circuit causes

longer turn off time on the load.

●

Use zener diode with zener

voltage about equal to power

supply voltage.

DIODE CIRCUIT

●

DC applications only.

●

Compared to RC type, circuit delays

longer turn off

time on the load.

●

For larger voltages, use diode with

reverse breakdown 10 times

circuit voltage and forward load

circuit.

●

For smaller voltages, use reverse

breakdown v or 2 to 3 X power

supply voltage.

RC CIRCUITS

●

This circuit is suitable for AC or DC

Contact applications, but if used

with AC voltage, impedance of the

load should be smaller than the RC

circuit

’

s. Do not utilize for timer

loads, as leakage current can

cause faulty operation.

●

This circuit is suitable for AC or DC.

If Circuit the load is a relay or

solenoid, release times lengthen.

90~120

20~30

150

180~200

220~240

Temperature(

℃

)

Time(s)

Preheating

Soldering

250

Max.

180

230

150

120

Max.

Temperature(

℃

)

Time(s)

Max.

Preheating

90~120

40~60

90~100

180~200

215

Temperature(

℃

)

Time(s)

Preheating

Soldering

Chlorinated Aqueous Alcoholic
Perochlene Indusco

IPA

Chlorosolder

Solvent

Holys Ethanol

Contact

lnductive load

Contact

SONG CHUAN

Technical Information

electrical equipment. In a relay it is the combination of a
coil form, the magnet wire coating, and the outer wrapping
of the relay coil.

A proper insulating system is essential because it
separates the control side of a relay (the coil) from the
switch side of the relay (the contacts). The switch side
of the relay may be used to switch high voltages that
are potentially lethal to humans as well as to the circuitry
that is connected to the coil side of the relay.

Consequently, when a relay is evaluated for a particular
project, it should be evaluated at the maximum ambient
temperature it will see in that product. If the insulating
system breaks down, it allows electrical current to flow
from the switch side of the relay to the control side of
the relay. This in turn causes failure--and in some cases
can present a safety hazard.

UL understands that time and temperature are the
enemies of an insulating system. Just as paint on a house
begins to peel with age and exposure to heat, aninsulation
system begins to break down with age and exposure to
heat. Consequently, UL designed and administers a series
of tests that assure that this breakdown does not occur
even after aging and heating.

UL Document 1446 is concerned with systems of
insulating materials. Insulating systems are classified by their
ability to withstand elevated temperatures. It is from this
document that we derive Class A, Class B, and Class F.

Table 3 is printed directly from the UL document. As it
indicates, a Class B relay is rated for a maximum hot spot
temperature of 130

℃

, and Class F relay is rated for a

maximum hot spot temperature of 155

℃

. For a relay, the

hot spot temperature is basically the coil temperature. The
coil temperature is a result of the self-heating of the coil
due to the power dissipation of the coil (coil voltage and
current), heating due to the load being carried by the
contacts (they get hot too and that leaks over to the coil),
and by the ambient temperature of the environment.

Effective when connected to both

contacts, power supply voltage

across the load is 100 to 200V.

●

As a guide in selecting c and r,

c: 0.5 to 1µF per 1A contact current,

r: 0.5 to 1Ω per 1V contact voltage.

VARISTOR CIRCUIT

●

Effective for AC & DC applications.

●

Circuit slightly delays release time.

Effective when connected to both

contacts, power supply voltage

across the load is 100 to 200V.

Inrush Current

The type of load combined with it

’

s inrush current

characteristics, together with switching frequency can
cause contact welding. For loads with inrush current,
measure the steady state current and inrush current to
determine the proper relay. Typical types of loads and the
inrush current they create are shown in Table 2. Note that
the effect of wiring resistance can reduce the inrush
currents to less than the levels shown.

■

TEMPERATURE

■

TOLERANT RELAY

More and more applications require relays that operate at
higher temperatures. Relays run "hot" due to high ambient
temperatures and/or high contact switching. These "hotter"
environments can destroy a relay's insulation system and
lead to product failure in the field.

To help prevent this type of failure, SONG CHUAN has,
for several years, offered UL Class A, Class B, Class F
insulating systems on its miniature power relays. Class F
relays have significant "heat" advantage over Class A or
Class B relays that, by contrast, only offer a rating of
105

℃

(Class A) or 130

℃

(Class B) .

This Class F insulating system is designated by UL and it
is rated at a full 155

℃

. This section is a discussion of why

and when an engineer needs to select a high temperature
rated for the application.

First, let's define an insulation system, as it pertains to
this application note. An insulation system may be defined
as simply any combination of insulating materials used in

lnductive load

Varistor

Contact

Table 2

Type of load

Inrush current

Resistive

Solenoid

Motor
Incandescent lamp 10~15 times the steady state current.

Mercury lamp

Sodium vapor lamp
Capacitive

Transformer

5~10 times the steady state current.

20~40 times the steady state current.

1~3 times the steady state current.

3 times the steady state current.

5~10 times the steady state current.

10~20 times the steady state current.

Steady state current.

Table 3

Max. Hot-Spot Temperature of Insulating Systems

System Class

℃

℉

130

266

155

311

180

356

200

392

220

428

240

464

Technical Information

SONG CHUAN

Technical Information

the non-complying product, or (iii) repay or credit the
customer an amount equal to the purchase price on the
non-complying product; provided that in no event shall
Song Chuan be responsible for warranty, repair,indemnity
or any other claims or expenses regarding the products
unless Song Chuan’s analysis confirms that the product
were properly handled, stored, installed, and maintained
and not subject to contamination, abuse, misuse, or
inappropriate modification.  Song Chuan must approve
return of any products by the customer in writing before
shipment.  Song Chuan Group Companies shall not be
liable for the suitability or unsuitability or the results from
the use of products in combination with any electrical or
electronic components, circuits, system assemblies or any
other materials or substances or environments.  Any
advice, recommendations or information given orally or in
writing are not to be construed as an amendment or
addition to the above warranty.

■

LIMITATION ON

LIABILITY

SONG CHUAN GROUP COMPANIES SHALL NOT BE
LIABLE FOR SPECIAL, INDIRECT, INCIDENTAL OR
CONSEQUENTIAL DAMAGES, LOSS OF PROFITS OR
PRODUCTION IN ANY WAY CONNECTED WITH THE
PRODUCTS, WHETHER SUCH CLAIM IS BASED IN
CONTRACT, WARRANTY, NEGLIGENCE OR STRICT
LIABILITY. Further, in no event shall liability of Song
Chuan Group Companies exceed the individual price of
the product on which liability is asserted.

At room temperature, most relay coils will not exceed a
temperature of 130

℃

even with full contact load and

continuous operation. However, if a particular circuit
design calls for the relay to work in a high ambient
temperature, or at a coil voltage higher than nominal (or
both)--it is possible that the coil temperature might exceed
130

℃

. Sometimes the designer does not realize this until

the product gets to UL--and at that point it is determined
that a higher class of insulating system is required. If the
Class B (rated up to 130

℃

) is not sufficient, Class F

(rated up to 155

℃

) would be the next logical choice.

Class F relays are proving to be ideal for applications
such as:

●

Appliance Controls

●

Automotive Controls

●

Spas and Pool Controls

●

Industrial Controls

Plus, as power relays are used more and more in control
application, and boards get smaller and smaller allowing
less room for heat dissipation--Class B and Class F relays
become increasingly attractive.

■

WARRANTY

Song Chuan’s exclusive warranty is that the Products will
be free from defects in materials and workmanship for a
period of twelve months from the date of sale by Song
Chuan.  Song Chuan disclaims all other warranties,
express or implied.  SONG CHUAN MAKES NO
WARRANTY OR REPRESENTATION, EXPRESSED OR
IMPLIED,  ABOUT NON-INFRINGEMENT,
MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE OF THE PRODUCTS.  BY PLACING A
PURCHASE ORDER WITH SONG CHUAN OR ITS
DISTRIBUTORS, THE CUSTOMER ACKNOWLEDGES
THAT THEY ALONE HAVE DETERMINED THAT THE
PRODUCTS WILL SUITABLY MEET THE
REQUIREMENTS OF THEIR INTENDED USE.

Song Chuan further disclaims all warranties and
responsibility of any type of claims or expenses based on
infringement by the Products or otherwise of any
intellectual property right. Song Chuan’s sole obligation
hereunder shall be, at Song Chuan’s election, to (i) replace
(in the form of originally shipped product with the customer
responsible for labor charges for removal and or
replacement thereof) the non-complying product (ii) repair