Finding the best isolation relay suitable for your needs isnt easy. With hundreds of choices can distract you. Knowing whats bad and whats good can be something of a minefield. In this article, weve done the hard work for you.
Reviews
1. Honeywell AT140A1000 40Va, 120V Transformer - 60 Hz.
Feature
Foot mounted, plate mounted, clamp mounted or panel mounted 120 Vac Transformer with Metal end bellsColor-coded leadwires for primary connections and screw terminals for secondary connections, fixed 1/4 inch (6 mm) male quick-connects or color-coded leadwires for both primary and secondary, are standard
Meet Underwriters Laboratories Inc. Standard UL 1585 and are identified. Class 2 not wet, Class 3 wet
Meet NEC Class 2 requirements
Foot mounted, plate mounted on 2x4 in. or 4x4 in. outlet box, clamp mounted using outlet box knockout, or panel mounted
Description
HONEYWELL 40 VA STEP DOWN TRANSFORMER *Converts 120V to 24V *Foot plate knockout mounting *120 primary voltage, screw terminals connections on secondary circuit *9" leadwire connections *Provides power to 24 vac circuits in heating / cooling systems *Intended for use in systems with predictable, uniform loads *UL listed2. Emerson 90-380 Relay, Fan, 24 VAC
Feature
Heavy-duty, general-purpose relay operates in any positionCompact, totally enclosed design with isolated coil and mounting bracket
For heating and cooling applications and general switching
Quiet, reliable and economical
SPNO switch action
Description
The White-Rodgers 90-370 heavy-duty relay is a totally enclosed relay, which operates in any position. This relay provides general-purpose switching for heating and cooling applications.3. White Rodgers 90-380 Replacement Heavy Duty Switching Fan Relay SPST 1-NO , 1-NC 24 V Coil
Feature
For heating and cooling applications and general switchingCompact, totally enclosed design
Operates in any position
Standard 1/4" Male TerminalsIndividually Boxed
Individually Boxed
Description
Brand New , Individually Boxed Replacement Fan Relay4. White Rodgers 90-370 Fan Relay Rbm Type 184 Heavy-Duty Enclosed
Feature
Heavy-duty, general-purpose relay operates in any positionCompact, totally enclosed design with isolated coil and mounting bracket
For heating and cooling applications and general switching
Quiet, reliable and economical
SPDT switch action
Description
The White-Rodgers 90-360 heavy-duty relay is a totally enclosed relay, which operates in any position. This relay provides general-purpose switching for heating and cooling applications.5. KNACRO 4-Channel Relay Module DC 24V with Optocoupler isolation H / L high / low Level Triger for Arduino
Feature
This module uses genuine quality relay, normally open interfaces Maximum load: AC 250V/10A, DC 30V/10AUsing SMD optocoupler isolation, driving ability, stable performance; trigger current 5mA
This module can be high or low by a jumper setting trigger
Fault-tolerant design, even if the control line is broken, the relay will not operate
If you need more technical support, just contact us on AMAZON!
Description
1. The module uses genuine quality relay, normally open interfaces Maximum load: AC 250V/10A, DC 30V/10A;2. Using SMD optocoupler isolation, driving ability, stable performance; trigger current 5mA;
3. The module Operating voltage 24V;
4. The module can be high or low by a jumper setting trigger;
5. Fault-tolerant design, even if the control line is broken, the relay will not operate;
6. The power indicator (green), the relay status indicator (red)
7. The interface design of human nature, all interfaces are available through a direct connection terminal leads, very convenient
8. Module size: 73mm*50mm*17mm (L*W*H)
Module interface:
1. DC+: positive power supply (VCC)
2. DC-: negative power supply (GND)
3. IN1,IN2,IN3,IN4: can be high or low level control relay
S1,S2,S3,S4, HIGHT OR LOW LEVER
Relay outputs:
1. NO1,2,3,4: normally open relay interface
2. COM1,2,3,4: Common Interface Relays
3. NC1,2,3,4: normally closed relay interface
High and low level trigger options:
It is low level trigger when jumper connect to LOW pin
It is high level trigger when jumper connect to HIGH pin
Package:
1*24V 4CH relay module
6. KNACRO SLA-12VDC-SL-C 1 Channel relay module DC 12V 10A With optocoupler isolation Support High level Low level (DC 12V 10A, 1-Channel)
Feature
Authentic quality module 30A relay, normally open interfaces Maximum load: AC 250V / 30A, DC 30V / 30A;SMD optocoupler isolation, driving ability, stable performance; trigger current 5mA;
Module voltage 5V, 12V, 24V to choose from; the module can be set high or low-level triggered by jumper;
Fault-tolerant design, even if the control line is broken, the relay will not operate; the power indicator (green), relay state indicator (red);
User-friendly interface design, all interfaces are available through the wiring terminal direct connection leads, very convenient.
Description
Relay version: 12V.Quiescent Current: 5mA.
Maximum current: 80mA.
Trigger current: 2 ~ 4mA.
Trigger voltage (low level): 0 ~ 4V.
Trigger voltage (high level): 4.5 ~ 12V.
Maximum load: AC 250V / 30A, DC 30V / 30A.
Module size: 50mm * 33mm * 24mm (L * W * H).
Product Weight: 36g.
There are four mounting bolts holes, hole 3.1mm, spacing 44.5mm * 27.5mm.
Module Interface Description:
DC +: positive module DC power supply (positive terminal voltage trigger)
DC-: DC power supply module negative electrode (anode terminal voltage trigger)
IN: Signal triggering end (default trigger the same voltage as power supply)
JD +: positive voltage relay control terminal
JD-: relay control terminal voltage of the negative
DC + and JD + with jumpered, DC- and JD- with jumpered, the same trigger terminal and relay control terminal voltage
High and low trigger mode selection, when the jumper is connected to L side, IN terminal is low trigger connection with the H for the high end trigger
Normally closed terminal (NC): relay normally closed terminal
Common terminal (COM): relay common
Normally open (NO): normally open relay
7. DZS Elec 12V 2 Channel High / Low Level Trigger with Optical Isolation Relay Module Fault Tolerant Design Load AC 0-250V/10A DC 0-30V/10A Circuit Switch Board
Feature
Can set high or low level trigger with jumper, to meet the demand of more trigger applications.With patch optical isolation, strong drive ability and stable performance, the trigger current is 5mA.
With Fault Tolerant Design, humanized terminals, even if the control line is broken, the relay will not take any action.
With green power light, red relay status indicator light, can directly reflect the current module working condition.
Input voltage is 12V, the max load of interface is AC 250V/10, DC 30V/10A.
Description
Feature:Module Size: 50*41*18.5mm
With 4 fixed bolt holes, diameter 3.1mm, spacing 44.5*35.5mm
High and low level trigger selection:
Trigger current is 2-4mA, trigger low level is 0-4V, trigger high level is 4.5-12V
1. S1 1 way relay high or low level trigger selection;
2. S2 2 way relay high or low level trigger selection;
3. com and low in short circuit, the relay is low level trigger, com and high end in short circuit, the relay is high level trigger.
Input Interface:
1. DC+: to connect the power positive (voltage as the relay required 12V)
2. DC-: to connect the power negative
3. IN1: 1 way signal trigger end, can set the high or low level control relay
4. IN2: 2 way signal trigger end, can set the high or low level control relay
Output Interface:
1. NO1: 1 way relay normally open interface, suspend the relay before pulling, then short connect with COM1
2. COM1:1 way relay common interface
3. NC1: 1 way relay normally close interface, short connect the relay with COM1 before pulling, then suspend
4. NO2: 2 way relay normally open relay interface, suspend the relay before pulling, then short connect with COM2
5. COM2: 2 way relay common interface
6. NC2: 2 way relay normally close interface, short connect the relay with COM2 before pulling, then suspend
Package Inlcude:
1pcs 12V 2 Channel High and Low Level Trigger Relay (Red Board)
8. HiLetgo 12V 1 Channel Relay Module With OPTO Isolation Support High or Low Level Trigger
Feature
Module uses genuine high quality relay, normally open interface maximum load: AC 250V / 10A, DC 30V / 10AUsing optocoupler chip isolation, strong drive capability, stable performance; trigger current 5mA
Module can be set by jumper high or low trigger
Fault-tolerant design, even if the control line is broken, the relay will not move
The interface design of human nature, all interfaces are available through a direct connection terminal leads, very convenient
Description
Module description:Module Size: 50mm * 26mm * 18.5mm (L * W * H)
With four fixed bolt holes, holes 3.1mm, spacing 44.5mm * 20.5mm
Power Indicator (green), Relay Status Indicator (red)
Interface:
Input:
VCC: Relay power supply +
GND: Relay power supply -
IN: Signal trigger input (High or Low Level Signal, select via jumper)
Output:
NO: Relay normally open.
COM: Relay Common Pin
NC: Relay normally closed.
Package Included
1*12V 1 Channel Relay Module With Optocoupler Isolation
How to provide an auto shut-down for Prusa i3 Mk2S?
1. Wired it in parallel with the power switch.
2. Use the hotend fan power as the trigger.
3. When you run a long print ,start the printer and when the hotend fan turns on (at about 50C) you can turn off the power switch.
4.The printer continues to run until the print is finished and the hotend cools below 50C. At that point the relay is no longer powered and the printer shuts itself off.
9. Leviton 29A00-1 Omnistat2 Thermostat Isolation Module
Feature
Only products shipped and sold by Amazon.com (not third-party sellers) are eligible for full warrantOptional module that may be needed for HVAC systems using non-standard voltages
For use when continuous 24-volt power is not available from the HVAC equipment
Easy installation with included mounting clips
In applications with separate heating and cooling units, product allows you to obtain power from one
Description
Relay isolation for Omnistat2 thermostats. This optional module may be needed for HVAC systems using non-standard voltages. Mounting clips and instructions are included. For use when continuous 24-volt power is not available from the HVAC equipment. It completely isolates an RC-80B series (Rc-8x) thermostat from the heating and cooling system and allows a separate 24-volt AC transformer (sold separately) to power the thermostat. This is necessary because the Omnistat2 receives power from the HVAC unit. If there are separate heat and cool units, this product allows you to only obtain power from one but control both.10. DC 12V 1-Channel 30A Relay Module Optocoupler Isolation High / Low Level Trigger
Feature
Isolation 1-Channel high-power relay control module, select the high signal trigger, only need 3mA current can drive control capability of 30A relay pull.The module uses high-quality relay, normally open interface Maximum load: AC 250V / 30A, DC 30V / 30A;The module uses high-quality power relay, ultra-small package optocoupler, high-power high-voltage transistor, red and blue signal indicator, double-sided PCB board, cloth board to consider a comprehensive, stable performance can be widely used in a variety of power control .The Module operating voltage 5V, 12V, 24V to choose from;
Relay high level pull, the module contains current limiting resistor, high level can be DC +, can also be single-chip I / O port set high;
Fault-tolerant design, even if the control line is broken, the relay will not work;Power indicator (red), 1-Channel relay status indicator (blue);, All interfaces can be directly connected through the terminal leads, very convenient; Module size: 6.0cm * 3.0m * 2.5cm (L * W * H); With 4 * 2.0MM diameter fixed bolt holes, easy to install;
Description
Module control: 4 interfaces, all interfaces have terminals, user-friendly wiring;1, DC +: External DC power supply negative (5V, 12V and 24V modules available)
2, DC-: external DC power supply negative;
3, VERF: photoelectric isolation control terminal reference ground, this signal should be connected to the user control panel power supply negative;
4, CH1: relay control interface, high level (relative to VERF) corresponding relay pull.
Note: the isolated relay module in order to adapt to the electromagnetic environment is relatively poor or relatively high signal requirements of the occasion, if you want to achieve a complete isolation effect, the user control panel power supply (that is connected to the VERF reference power) and the relay module power supply (DC + / DC-) should be separated, if the two power supply shared ground, then the effect is not fully isolated, then the user can use the standard relay module.
Relay output: 3 interfaces, all interfaces have terminals;
1, NO: relay normally open interface;
2, COM: relay common interface;
3, NC: relay normally closed interface;
Package Included:
1*DC 12V 1-Channel 30A Relay Module