Numato Lab 1 Channel Relay breakout User manual

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1 Channel Relay Breakout (30A)
User Gui e

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1 1 Channel Relay Breakout (30A) – User Gui e
Intro uction
Numato Lab's 1 Channel Relay breakout mo ule (30A) is a smart choice for controlling higher current
loa s from your microcontroller evelopment boar or a PC parallel port. This boar has a single SPDT
relay which can switch up to 30A (Use the terminals on the top of the relay for han ling current in
excess of 10 A). The relay terminals (COM, NC, NO) are accessible through screw terminals which
makes wiring up the boar very easy. Relay coil is rate for 12VDC. A flyback io e is use to eliminate
the su en voltage spike across the relay loa when the voltage is re uce or remove . Opto isolate
input is an a e a vantage of this boar which separates the relay circuit electrically from TTL input.
Some of the possible uses of this mo ule inclu e
•Home Automation
•Lighting Control
•Gar en Equipment Control
•In ustrial Automation
•Test Fixtures
•DIY an Hobby
This mo ule has one on boar relays an associate rivers capable of controlling a large number of
evices inclu ing lamps, motors, locks etc...
Features
•Very compact an easy to wire up.
•Connects irectly to TTL evices (Microcontrollers, Ar uino etc..).
•One Relay with three pin screw terminals for easy connectivity.
©2015 NUMATO SYSTEMS PVT LTD
www.numato.com

2 1 Channel Relay Breakout (30A) – User Gui e
How to use the module
The following section escribes how to use this mo ule.
Components/Tools required
Along with the mo ule, you may nee the items in the list below for easy an fast installation.
1. 12V DC Supply
2. Me ium size Philips screw river
Connection Details
MPORTANT Please exercise utmost caution while working with electrical mains or other
high voltages. Failure to comply with safety regulations may result in injury and or death.
Connection Diagram
Above image shows basic connection iagram that can be use in most of the situations. The
connection iagram is same for both AC an DC loa s. Please make sure to use a freewheeling io e
or snubber circuit if the loa is in uctive. More etails about using in uctive loa s is available
elsewhere in this ocument. It is important to make sure that the wires use to connect loa s are
sufficiently rate to han le expecte loa current. Exercise caution while working with high voltages.
The following sections i entify in ivi ual connections in etail.
©2015 NUMATO SYSTEMS PVT LTD
www.numato.com

3 1 Channel Relay Breakout (30A) – User Gui e
Relay Contacts
This mo ule has one 12V DC mechanical relay that can switch up to 30A of current. All contacts on
each relay is available externally on screw terminals for easy user access. The
relays are rate for AC an DC supply voltages. Please see the electrical
parameter table for more etails. Relay has three contacts(COM, NO an NC).
COM is the common terminal an is use in both normally open an normally
close positions. The contacts NC an COM will be connecte when the relay is
turne off an will be isconnecte when relay is turne on. An viceversa, the
contacts COM an NO will be isconnecte when relay is turne off an will be
connecte when the relay is turne on. Table below summarizes possible relay contact positions.
Relay State Connection between NC an
COM
Connection between NO an
COM
OFF Close Open
ON Open Close
DC Power Supply
This mo ule uses +12V supply for the relay coils. The +12V supply for the relay coils is not optional
an the relay will not switch without this supply. Any off the shelf 12V DC power supply can be use
for this purpose. Make sure to connect the power supply in correct polarity. Connect the positive
terminal of the power supply to the +12 terminal on the mo ule. Connect negative terminal of the
power supply to GND terminal of the mo ule. Connecting power supply incorrectly can cause amage
to the mo ule an /or other evices.
Triggering Relay
The relay on the boar can be either turne on by using micro controller or DC supply. The triggering
pin is marke as NPUT on the boar .
©2015 NUMATO SYSTEMS PVT LTD
www.numato.com

4 1 Channel Relay Breakout (30A) – User Gui e
A itional Information
Using relay mo ules with in uctive loa s
It is important to take a itional care when using relays with in uctive loa s. An in uctive loa is
pretty much anything that has a coil an works base on magnetic principles like Motors, Solenoi s
an transformers. In uctive loa s pro uce back emf when the magnitu e of the loa current changes.
The back emf can be in the or er of tens or even hun re s of voltage (See this Wikipe ia article
http://en.wikipe ia.org/wiki/Counter-electromotive_force). This effect is most severe when power is
isconnecte from in uctive loa because the rate of change of current is maximum at that point.
Even though the back emf lives only for a very short time (a few millisecon s) it can cause sparks
between the relay contacts an can eteriorate the contact quality over time an re uce the life span
for the relays consi erably.
So it is important to take countermeasures to suppress the back emf to acceptable levels to protect
relay contacts. Usually this requires connecting electronic evices in parallel with the loa such that
they absorb the high voltage components generate by the loa . For solenoi s, connecting a io e
(fast switching io e is recommen e ) in parallel to the
loa (in reverse irection to the loa current) is very
effective. A io e use for this purpose is usually calle a
freewheeling io e. Please see the iagram on the right
for connection etails.
A capacitor with proper rating is recommen e for protecting the relay contacts when a motor is use
as loa . The capacitor shoul be rate enough to withstan the back emf that is generate by the
motor. Please see the iagram below for connection etails.
©2015 NUMATO SYSTEMS PVT LTD
www.numato.com

5 1 Channel Relay Breakout (30A) – User Gui e
Please note that the relay mo ules are NOT shippe with back emf suppression evices pre-installe .
The exact kin of suppression evice an the parameters of the selecte evice can vary epen ing
on the loa itself. Some of the parameters that affects the suppression evice selection are the
in uctance of the loa , power supply voltage, loa current, physical size/structure of the loa etc.. It
is obvious that it is impossible for us to pre ict these parameters an esign require back emf
suppression evice an incorporate that on the boar . So we believe this is a task best left to the
mo ule user. There is an excellent article on esigning back emf suppression on Wikipe ia at
http://en.wikipe ia.org/wiki/Flyback_ io e
©2015 NUMATO SYSTEMS PVT LTD
www.numato.com

6 1 Channel Relay Breakout (30A) – User Gui e
Technical Specifications
Parameter * Value Unit
Basic Specifications
Number of relays 1
Relay Specifications
Nominal relay coil voltage 12 V
Relay contact Form 1A/1B/1C
Relay contact material AgC O, AgSnO2
Contact Ratings 1A: 30 A 240VAC,30VDC
1B: 20A 240VAC,30VDC
1C: 30 A /20A 240VAC,30VDC
Maximum switching voltage 250V AC/110V DC
Maximum switching current 30 A
Maximum switching power 7200VA/1100W
Contact resistance (initial) <30 mΩ
Life expectancy (Electrical) 100,000 Operations
Life expectancy (Mechanical) 10,000,000 Operations
Nominal insulation resistance 1000 MΩ
Maximum switching on response time 15 mS
Maximum switching off response time 10 mS
* All parameters consi ere nominal. Numato Systems Pvt Lt reserve the right to mo ify pro ucts without notice
*http://kyotarelays.com/ atasheets/KT%20918.p f
©2015 NUMATO SYSTEMS PVT LTD
www.numato.com

7 1 Channel Relay Breakout (30A) – User Gui e
FAQ
Q. I nee a customize version of this pro uct, can Numato o the customization for me?
A. Yes, we can efinitely o customization but there may be minimum or er requirements epen ing on the level of
customization require . Please write to [email protected] for a quote.
Q. Where can I buy this pro uct?
A. All Numato pro ucts can be or ere irectly from our web store http://www.numato.com. We accept major cre it
car s an Paypal an ship to almost all countries with a few exceptions. We o have istributors in many countries where
you can place your or er. Please fin the current list of istributors at http://numato.com/ istrib.
©2015 NUMATO SYSTEMS PVT LTD
www.numato.com

8 1 Channel Relay Breakout (30A) – User Gui e
Physical Dimensions
Schematics
See next page.
©2015 NUMATO SYSTEMS PVT LTD
www.numato.com

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Date: 17 jun 2015
KiCad E.D.A. Rev:Size: A4 Id: 1/1
Title: 1RelayBreakout30A
File: 1RelayBreakout.sch
Sheet: /
Numato Lab
http://www.numato.com
License : CC BY-SA
C2
0.1uF
PWR_FLAG
GND 1
2
P2
1
2
P1
R1
2K2
12V
1
2 3
4
U1
PC817
C1
100uF
12V
GND
RL0
GND
12V
12V
12
34
5
RL1
RELAYSUGARCUBE
12
D1
LED R2
2K2
R5
1K
D2
SM4007
1 2 3
K2
R3
2K2
GND
R4
2K2
C3
100uF
R6
2K2
R7
2K2
C4
100uF
C5
100uF
D3
SM4007
D4
SM4007
B
1
E
2C
3
Q1
MMBT2222
NC COM NO