Why Do Relays Use 30, 85, 86, 87, 87a?

The relay you described is Single Pole Double Throw. As far as the numbers, not sure. Never even thought about it.Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

They follow guidlines setup by an electrical standards guidelines. I can't remember the organization that standardized the numbers system specifically, but essentially, there is a guide that tells how the numbers are assigned based on funtion and timing (when it was proposed and approved) Something like how the NFL uses certain sets of numbers for certain positions.Never send your ducks to eagle school.

The difference between ordinary and extraordinary is that little extra.

The 3Ls of life: Learn from the Past, Live for the Present, Look to the Future.

The UK quattro Network

Automotive component pin assignmentsYes, it's perfectly true. All those little numbers barely perceptibly cast in the bases of automotive relays are standardized! Who knows - the following list may be helpful in emergencies, although it may not be complete or entirely correct:Ignition and current supplyCode Function1 Coil, distributor - low voltage1a To contact breaker I (distributor with 2 separate circuits)1b To contact breaker II (distributor with 2 separate circuits)2 Shorting circuit - magneto ignition4 Coil, distributor - high voltage4a From coil I (distributor with 2 separate circuits)4b From coil II (distributor with 2 separate circuits)7 Ballast resistor terminal to/from distributor15 Switched + downstream of battery (output of ignition/driving switch)15a Output at ballast resistor to coil and starter17 Glow plug and starter switch - Start19 Glow plug and starter switch - Preheat30 Input from battery +, direct 12/24 V series-parallel battery switch30a Input from + terminal of battery II31 Battery negative terminal, or ground, direct31a Return line to battery II, negative (12/24 V series-parallel battery switch)31b Return line to battery negative terminal, or ground via switch or relay (switched negative)31c Return line to battery I, negative (12/24 V series-parallel battery switch)XBattery power switched through the load reduction relay MotorsCode Function32 Return33 Main terminal connection33a Self-parking switch-off33b Shunt field33f For 2nd low-speed range33g For 3rd low-speed range33h For 4th low-speed range33L Anticlockwise33R  ClockwiseStartersCode Function45 Separate starter relay, output; starter, input (main current)Two-starter parallel operation - Starting relay for engagement current45a Output, starter I, Input, starters I and II45b Output, starter II 48 Terminal on starter & on repeating relay for monitoring starting procedureTurn-signal flashers (pulse generators)Code Function49 Input49a Output49b Output, 2nd circuit49c Output, 3rd circuitStarter controlCode Function50 Starter control (direct)50a Series-parallel battery switch - Output for starter controlwith parallel operation of two starters with sequential control 50b Starting relay for sequential control of the engagement currentduring parallel operation of two starters50c Input at starting relay for starter I50d Input at starting relay for starter II50e Start-locking relay Input50f Start-locking relay Output50g Start-repeating relay Input50h Start-repeating relay OutputAlternatorCode Function51 DC voltage at rectifier51e DC voltage at rectifier with choke coil for daytime drivingTrailer signalsCode Function52 Additional signals from trailer to vehicleWiper motorsCode Function53 Wiper motor, input (+)53a Wiper (+), self-parking switch-off53b Wiper (shunt winding)53c Electric windshield-washer pump53e Wiper (brake winding)53I Wiper motor with permanent magnet and 3rd brush(for higher speed)Trailer signals (see also 52)Code Function54 Trailer plug connections and lighting combinations, brake light54g Pneumatic valve for continuous brake in trailer, solenoid-operatedLightingCode Function55 Fog lamp56 Headlamp56a High beam, high-beam indicator lamp56b Low beam56d Headlamp-flasher57a Parking lamp57L Parking lamp, left57R Parking lamp, right58 Side-marker, tail, numberplate and instrument panel lamps58b Taillight changeover for two-wheeled tractors58c Trailer plug and receptacle assembly for single-conductor tailight with fuse in trailer58d Variable intensity instrument panel light, tail light and side marker.58L Numberplate lamp, left58R Numberplate lamp, rightAlternators and voltage regulatorsCode Function59 A/c voltage output, rectifier input59a Charging armature, output59b Tail light armature, output59c Brake light armature, output61 Alternator charge-indicator lampB+ Battery +B- Battery -D+ Dynamo +D- Dynamo -DF Dynamo fieldDF1 Dynamo field 1DF2 Dynamo field 2U,V,W Three-phase alternator terminalsMulti-tone horn and emergency lightsCode Function71 Input71a Output to horns 1 & 2 low71b Output to horns 1 & 2 high72 Alarm switch - revolving emergency lightRadio, cigarette lighterCode Function75 Radio, cigar lighter76 Speakers77 Door valve controlNormally closed and changeover switchesCode Function81 Input81a Output 1, NC side81b Output 2, NC sideNormally open switchesCode Function82 Input82a Output 182b Output 282z Input 182y Input 2Multi-position switchesCode Function83 Input83a Output, position 183b Output, position 283L Output, left-hand position83R Output, right-hand positionCurrent relaysCode Function84 Input, actuator and relay contact84a Output, actuator84a Output, relay contactSwitching relaysCode Function85 Output, actuator (end of winding to ground or negative)86 Input, actuator (start of winding)86a Start of winding or 1st winding86b Winding tap or 2nd windingRelays - N/C and changeoverCode Function87 Input87a Output 1(NC side)87b Output 287c Output 387z Input 187y Input 287x Input 3Relays - N/O and changeoverCode Function88 Input88a Output 188b Output 288c Output 388z Input 188y Input 288x Input 3Directional signalsCode FunctionC Indicator lamp 1C2 Indicator lamp 2C0 Main connection for separate indicator circuitsworked by turn signal switchC3 Indicator lamp 3 (e.g., when towing two trailers)L Turn-signal lamps, leftR Turn-signal lamps, rightKerbside Motors Home Page and Contact Information http://www.isham-research.com/quattro/wiring/Typ85/terminals.html

From Bosch Automotive Handbook, 3rd edition

Terminal Designations (Excerpts from DIN Standard 72 552)The terminal designations do not identify the conductors, because devicewith different terminal designations can be connected at the two ends ofeach conductor. If the number of terminal designations is notsufficient (multiple-contact connections), the terminals areconsecutively numbered using numbers or letters whose representationsof specific functions are not standardized. <>

Terminal Definition

-----------------------------------------------------------------------

IGNITION

1 Ignition coil, ignition distributor, low voltage

-----------------------------------------------------------------------

(Ignition distributor with two separate electrical circuits)

1a to ignition contact breaker I

1b to ignition contact breaker II

-----------------------------------------------------------------------

2 short-circuit terminal (magneto ignition)

4 Ignition coil, ignition distributor, high voltage

-----------------------------------------------------------------------

(ignition distributor with two separate electrical circuits)

4a from ignition coil I, terminal 4

4b from ignition coil II, terminal 4

-----------------------------------------------------------------------

15 Switched + downstream of battery

(output of ignition/driving switch)

15a Output at dropping resistor to ignition coil and starter

-----------------------------------------------------------------------

GLOW PLUG AND STARTER SWITCH

17 Start

19 Preheat

-----------------------------------------------------------------------

BATTERY

30 input from + battery terminal, direct

30a input from + terminal of battery II

(12/24 V series-parallel battery switch)

31 Return line to battery

- battery terminal or ground, direct

31b Return ine to negative battery terminal or ground, via switch

or relay (switched negative)

-----------------------------------------------------------------------

(12/24 V series-parallel battery)

31a Return line to - terminal of battery II

31c Return line to - terminal of battery I

-----------------------------------------------------------------------

ELECTRIC MOTORS

32 Return line

(Polarity reversal possible at terminals 32-33)

33 Main terminal connection

(Polarity reversal possible at terminals 32-33)

33a Self-parking switch-off

33b Shunt field

33f For second lower-speed range

33g For third lower-speed range

33h For fourth lower-speed range

33L Counterclockwise rotation

33R Clockwise rotation

-----------------------------------------------------------------------

STARTER

45 Separate starter relay, output; starter input (main current)

45a Output, starter I

Input, starters I and II (Two-starter parallel operation)

45b Output, starter II (Two-starter parallel operation)

48 Terminal on starter and on start-repeating relay for

monitoring starting procedure

-----------------------------------------------------------------------

TURN SIGNAL FLASHER

49 Input

49a Output

49b Output, second turn-signal circuit

49c Output, third turn-signal circuit

-----------------------------------------------------------------------

STARTER

50 Starter control (direct)

50a Output for starter control

(Series-parallel battery switch)

50b Starter control with parallel operation of two starters with

sequential control

50c Input at starting relay for starter I

(Starting relay for sequential control of the engagement

current during parallel operation of two starters)

50d Input at starting relay for starter I

(Starting relay for sequential control of the engagement

current during parallel operation of two starters)

50e Input, Start-locking relay

50f Output, Start-locking relay

50g Input, Start-repeating relay

50h Output, Start-repeating relay

-----------------------------------------------------------------------

ALTERNATOR

51 DC voltage at rectifier

51e DC voltage at rectifier with choke coil for daytime driving

-----------------------------------------------------------------------

TRAILER SIGNALS

52 Signals from trailer to towing vehicle, general

-----------------------------------------------------------------------

WIPER MOTOR

53 Wiper motor, input (+)

53a Wiper (+), self-parking switch-off

53b Wiper (shunt winding)

53c Electric windshield-washer pump

53e Wiper (brake winding)

53i Wiper motor with permanent magnet and third brush (for higher

speed)

-----------------------------------------------------------------------

TRAILER SIGNAL

54 For lamp combinations and trailer plug connections

TRAILER STOP LAMP

54g Pneumatic valve for additional retarding brake,

electromagnetically actuated

-----------------------------------------------------------------------

LIGHTING

55 Fog lamps

56 Headlamp

56a High beam, high-beam indicator lamp

56b Low beam

56d Headlamp-flasher contact

57 Side-marker lamp: motorcycles, mopeds.

Abroad also cars, trucks, etc.

57a Parking lamp

57L Parking lamp, left

57R Parking lamp, right

58 Side-marker lamps, tail lamps, license-plate lamps and

instrument-panel lamps

58b Tail-lamp changeover for single-axle tractors

58c Trailer plug-and-receptacle assembly for single-conductor

tail-lamp cable with fuse in trailer

58d Variable-intensity instrument-panel lamp, tail-lamp and

side-marker lamp

58L Side-marker lamp, left

58R Side-marker lamp, right; license-plate lamp

-----------------------------------------------------------------------

ALTERNATOR (magneto, generator)

59 AC voltage, output

Rectifier, input

59a Charging armature, output

59b Tail-lamp armature, output

59c Stop-lamp armature, output

61 Alternator charge-indicator lamp

-----------------------------------------------------------------------

TONE-SEQUENCE CONTROL DEVICE

71 Input

71a Output to horns 1 & 2, low

71b Output to horns 1 & 2, high

72 Alarm switch (rotating beacon)

-----------------------------------------------------------------------

INTERIOR

75 Radio, cigarette lighter

76 Speaker

77 Door-valve control

-----------------------------------------------------------------------

SWITCHES

----------(Break-contact and changeover switches)----------------------

81 Input

81a 1st output, break side

81b 2nd output, break side

----------(Make-contact switches)--------------------------------------

82 Input

82a 1st output

82b 2nd output

82z 1st input

82y 2nd input

----------(Multiple-position switches)---------------------------------

83 Input

83a Output, position 1

83b Output, position 2

83L Output, left-hand position

83R Output, right-hand position

-----------------------------------------------------------------------

CURRENT RELAY

84 Input, actuator and relay contact

84a Output, actuator

84b Output, relay contact

-----------------------------------------------------------------------

SWITCHING RELAY

85 Output, actuator (end of winding to ground or negative)

86 Start of winding

86a Start of winding or 1st winding

86b Winding tap or 2nd winding

----------(relay contact for break and changeover contacts)------------

87 Input

87a 1st output (break side)

87b 2nd output

87c 3rd output

87z 1st input

87y 2nd input

87x 3rd input

----------(Relay contact for make contact)-----------------------------

88 Input

----------(Relay contact for make and changeover contacts (make side))-

88a 1st output

88b 2nd output

88c 3rd output

----------(Relay contact for make contact)-----------------------------

88z 1st input

88y 2nd input

88x 3rd input

------------------------------------------------------------------------

ALTERNATOR and VOLTAGE REGULATOR

GENERATOR and GENERATOR REGULATOR

B+ Battery positive

B- Battery negative

D+ Dynamo postive

D- Dynamo negative

DF Dynamo field

DF1 Dynamo field 1

DF2 Dynamo field 2

----------(Alternator with separate rectifier)--------------------------

J Excitation winding positive

K Excitation winding negative

Mp Center point terminal

U,V,W Alternator terminals

------------------------------------------------------------------------

DIRECTION INDICATOR (turn-signal flasher)

C First indicator lamp

C0 Main terminal connection for separate indicator circuits

actuated by the turn-signal switch

C2 Second indicator lamp

C3 Third indicator lamp (e.g., when towing two trailers)

L Turn-signal lamps, left

R Turn-signal lamps, right

------------------------------------------------------------------------

Cross-reference for old and new terminal designations in accordance with

DIN 72 552.

Only terminal designations whose significance has altered are given.

OLD NEW

1 1, 53(wiper), 53e

2 2, 53e

3 53, 53b(wiper)

4 4, 53a, 53b(wiper)

15 15, 49(turn-signal flasher)

15+ 49

15/54 15, 49, 54

16 15a, 15

30 30, 33(motor)

30/51 30, 87, 88(relay)

30f 45

30h 45, 45a

30h I 45a

30h II 45b

30L 33L (motors)

30R 33R (motors)

31 31, 31c, 32(motors)

31a 31a, 31c

31B- B-

50 50, 50b, 50f, 50h

50a 50, 50a, 50e, 50g

50b 50d

50k 50d

50 II 50c

51 51, 59, B+

51 - 59

51a 59

51B+ B+

54 54, 53a, 54g

54/15 15

54d 53(wiper)

54e 33b, 53b(wiper)

54L 49a

58 58, 58L, 58R

58b 58b, 58d

59 59a

85d 31b(alarm switch)

B+30 B+

B+51 B+

D+/61 D+

D-/61 D-

H 71

HL L (L54b)

HR R (R54b)

K C

K0 C0

K1 C, C2

K2 C2

K3 C2, C3

K4 C2, C3

L54 L (L54)

N 55

P C, 57a

PL 57L

PR 57R

R R, 75

R54 R, (R54)

R54b Rb

S 49a, 53(wiper)

S4 49a

SBL (L54)

SBR (R54)

VL L

VR R

+ 15, 49(turn-signal flasher)

53, 53a(wiper)

+2 53a

+15 49

- 1 (ignition coil), 31

------------------------------------------------------------------------

and, while i'm at it, here's some interesting stuff:

Power consumption of vehicle electrical leads (average values)

Backup lamps 25W

Battery ignition 20W

Blower motor 80W

Cigarette lighter 100W

Fog lights 35W each

Fog warning lamp 35W

(red fog light on rear)

Glow plugs 100W each

Headlamps, low beam 55W each

Headlamps, high beam 60W each

Heated rear window 120W

Horns and fanfare horns 25W...40W each

Instrument-panel lamps 2W each

Interior lamp 5W

License-plate lamp 10W

Parking lamp 3W...5W

Radio 10W...15W

Side-marker lamps 4W each

Starting motor for truck 2.2kW...12kW

Starting motor for car 0.8kW...3kW

Stop lamps 18W each

Tail lamps 5W each

Turn-signal lamps 21W each

Vehicle heater 20W...60W

Windshield wiper 90W

http://www.members.shaw.ca/bilbo/bosch.html

John DeRosa (Hotwaterwizard)

Stockton California

When in doubt, try it out !

Hotwaterwizard.....now THATS an answer.

Most do, as this has become standardized numbering, based on Bosch's interpretation of DIN Standard 72-552 which deals with most electrical wiring. Notable deviations from original DIN to Current Ver-6 DIN | Bosch | Terminal 87 30 Common Relay Contact 87b 87 Normally Closed Contact

I hope there isn't a test on this. It's always nice to learn new things. sparky