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Questions tagged [relay]

A relay is a control device that allows a small voltage or current to control a larger voltage or current. Use this tag for questions about standalone relays in electrical or HVAC wiring -- questions about relays in appliances do not need this tag.

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Sprinkler Pump Outdoor Plug with Relay

We recently bought a home that had a shed, which we removed. The shed housed a run of cable to a sprinkler pump at the back of the property. It also housed the pump start relay. The shed is now gone ...
ian's user avatar
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1 vote
2 answers
51 views

Using "dumb" fan control switch as a remote

I have a standard 3-speed fan and dimmable light bulb that I would like to control independently using this specific "dumb" switch, with two independent dimmers for the fan speed and light ...
user84207's user avatar
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1 answer
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How do I fix a noisy humidistat/relay?

I have a Rudd furnace with a Honeywell home humidistat. It seems like when the humidity in the house get to the same setting that the humidistat is set to, that the relay opens and closes about a ...
Keith Miller's user avatar
0 votes
1 answer
102 views

Can RPM Sensor cause short circuit? Craftsman 1/2 HP Garage Door Opener Model 139 Relay (Power Board) trips as soon I connect the RPM sensor

I'm facing an issue with my Craftsman 1/2 HP Garage Door Opener Model 139. I found it dead one morning, no power, no led light was lit in the head unit, and wall controller light was flickering. On ...
Amith Kumar's user avatar
3 votes
1 answer
77 views

Fridge died for New Years eve. Should I replace the overload protector or the whole relay? (full details, testing inside)

Fridge: Sears 970-681020 Combination relay: 213615005 (embraco/eecon tsd-115/127v-60hz-y) Compressor: egz 70hlp embraco Symptoms: Click, BRRRRR (4 seconds), Click....... no cooling Tests: Pulled the ...
Ambiwlans's user avatar
  • 141
1 vote
1 answer
37 views

Controlling 15amp outlet for compressor with Honeywell RC840T-120 and 18g wire to toggle

I have a compressor in my crawlspace that I'd like to turn on by using a low volt toggle. I was planning to use Honeywell RC840T-120 such that my 18g wire is hooked up to the 24v leads and causes the ...
Fresh Codemonger's user avatar
5 votes
2 answers
689 views

Do I need a junction box for thermostat wire splices?

I have an oil fired heating system with 4 zones heated with baseboards. I recently noticed that one of the zones stopped working because its thermostat wire in the basement was frayed. I removed that ...
shackleton's user avatar
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106 views

Thermostat Wiring for Zoned Hydronic Heating

I have a 7 zone circulator pump heated using Navien combi-boiler. 3 thermostats are connected to the boiler, and the remaining 4 are connected to a Taco SR-504 relay. All the connections have 2 wires, ...
Steve's user avatar
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0 votes
3 answers
116 views

Single pole relay on a 240VAC split phase circuit?

I'm installing an EV charger but my panel is only big enough to run either the dryer or the EV charger at the same time. So I have a current sensor on the dryer line so that when the dryer is running ...
Wise Shepherd's user avatar
2 votes
2 answers
408 views

How can I simultaneously disable an inverter (that draws big currents) when switching off another circuit?

I have the setup below in my cabin. Currently I have to manually turn off the inverter for the 220V as well as the main switch when leaving the cabin. I would like the main switch to control both, by ...
oligofren's user avatar
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How can I test a potential relay on my AC

My starter capacitor failed so I installed another one and it failed also.I was told if the relay failed it could blow the capacitor. I tested the relay and it is normally closed, how can I test it to ...
Mirage's user avatar
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0 answers
65 views

Is the start relay for my Whirlpool broken? It rattles

My fridge has stopped cooling and with some cursory research I've determined that the problem may be the start relay. I've seen this diagnosed by shaking it to listen to any rattling sound. Does this ...
Amon's user avatar
  • 101
1 vote
0 answers
37 views

Thermostat relay access

After nearly 30 years in my 1950s-era home, I'm finally getting around to finishing the basement. I'd like to put up a drywall ceiling, but this device, which I believe is the thermostat relay (to a ...
kellymac's user avatar
0 votes
1 answer
149 views

Wiring a SPDT relay to AC 120V

My use is for switching guide wires for a Husqvarna Automower setup. I want to have two separate guide wires going through two separate gates. The SPDT will be used to switch between the two guide ...
Sumit's user avatar
  • 103
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1 answer
1k views

Danby Mini-fridge not Cooling

I have a Danby Designer mini fridge (‎FBA_DCR032A2BDD) that stopped cooling recently. This fridge was only been manufactured in 2019 so it feels like a waste to throw it out without at least ...
GeorgeCiesinski's user avatar
5 votes
1 answer
861 views

What is the correct way to wire a Relay In Box (or similar relay) that has low-voltage signal wires bundled with 120V wires?

It is my understanding that low-voltage wires can share a double-gang box with 120V wires, as long as they are isolated from each other by a permanent divider. I was looking at getting this relay to ...
User41943's user avatar
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1 vote
1 answer
389 views

Replacing old Trane relay with new Trane contactor

Would this be the correct orientation for replacing an old Trane relay with a new Trane contactor? It looks like the 4 flathead screw/lugs on either end match up with the 4 screw terminals on the ...
TheBigCat's user avatar
5 votes
3 answers
2k views

Is it a Contactor or is it a Relay?

Why do HVAC pros mix terms like "relay" and "contactor"? Here's an example of a 'contactor' being called a "Contactor Relay". Also, I've seen online supply houses using ...
TheBigCat's user avatar
0 votes
1 answer
168 views

Can I replace a 2 Pole 24V/50A contactor with a 2 Pole 24V/40A one? [closed]

I have an old Trane Executive AC [BTD736A100B0] unit that uses contactor-relay RLY03346. I've seen plenty of 2 Pole 24V 40A contactors available, but the Trane RLY03346 contactor is actually a 2 Pole ...
TheBigCat's user avatar
1 vote
0 answers
355 views

Submersible pump starter - choosing the right relay

A few months ago our submersible pump starter stopped working and the local repair shop guy diagnosed it as a relay issue and replaced it. While the starter is working fine since then, my concern ...
Chethan S.'s user avatar
0 votes
1 answer
480 views

Use one Ecobee thermostat to control three electric baseboard heaters with Aube RC840 relays?

We have a number of electric baseboard heaters in our house that I would like to smarten up. Eventually I intend to get rid of these baseboard heaters, and replace them with a better heating system, ...
Josh Ourisman's user avatar
2 votes
0 answers
144 views

Is there a solid-state version of this relay/transformer combo?

One-line summary: Is there a solid-state version of the White Rodgers 90-113 Fan Control Center (Transformer and Relay Combination)? EDIT to answer question: The thermostat draws 0.146A (3.5VA / 24V). ...
ron rothman's user avatar
2 votes
0 answers
161 views

How to wire relay for heat-pump/boiler with backup heater

I have two heat-pumps controlled by a tekmar 262 boiler control. The heat pumps heat water in a storage tank, which is then circulated through the house. The storage tank is designed for hydronic ...
Gary Aitken's user avatar
0 votes
2 answers
637 views

Wiring infrared patio heater

I am installing a 4000W infrared heater in our new patio. The supply for this heater is a single phase 240V connection (rated at 16amps, so I'll use a 20amp breaker). I would like advice on two things....
5000fingers's user avatar
0 votes
4 answers
885 views

Is there any possibility I could use WD40 to unstick a furnace fan center relay?

I've recently run into an issue this winter, where the fan center relay in the furnace for the house I'm living in has begun to stick closed, when the thermostats call it for heat. It is a hydronic ...
Tallguy5292's user avatar
0 votes
0 answers
361 views

Need some help with wiring a Shelly Plus 1 to fireplace

Trying to figure out how to wire up a Shelly Plus for Alexa control to turn on/off a gas ventless fireplace. Been reading this guide but I can't figure out how the gas valve gets wired. Here is my ...
amrog's user avatar
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0 answers
54 views

Replacing stove solid-state-relay

I am replacing a relay for an appliance (stove) I cannot find a replacement relay, however I thought I'd confirm if the following relays would be compatible: The original relay is: input 90-250 VAC ...
SpcSnuffy's user avatar
1 vote
2 answers
212 views

240v heater with RIB01P30 relay for timer switch

I have a 240v 30 amp heater that I want to hook up a 120v push button timer to (neutral required for timer switch). I bought this RIB01P30 relay but am having some trouble wiring it up. This is the ...
Joshua Young's user avatar
1 vote
1 answer
694 views

Electric furnace fan won't stop sometimes, however it does turn on okay

I have a York Electric Furnace (10 years old) with a outside heat pump. Something weird happened recently as we started to use the furnace more often as it gets cold now. I usually turn on the heat ...
MIDNIGHT LAWN MOWER's user avatar
4 votes
4 answers
2k views

How to control multiple independent circuits from one switch?

If I have several separate circuits in my house, each with their own circuit breaker, how can I turn all of them on or off with only one switch? The circuits could be all of one voltage and amperage, ...
Triplefault's user avatar
  • 7,877
0 votes
0 answers
97 views

Standard boiler wiring

My oil powered boiler's controller is terrible and commercial replacements are expensive. So, I'm going to make my own. Looking at the back of the existing controller, there's this wiring diagram ...
ScottishTapWater's user avatar
1 vote
3 answers
640 views

240v heater from 120v countdown timer switch using a relay

I have a 240v 30amp infrared ceiling mounted heater in my garage for cold days when I want to work out there. It's controlled by a wall mounted thermostat by the same brand (Dr. Heater). I just ...
Joshua Young's user avatar
0 votes
1 answer
94 views

Do small parallel bypass switches for electrical panel exist?

I would like to install ethernet commanded relays between the breakers and the "house" (relays ref https://www.dingtian-tech.com/en_us/relay8.html#). However, I would also like to bypass the ...
Florian S.'s user avatar
0 votes
0 answers
44 views

Using different relay for refrigerator’s card

My refrigerator’s electonic card has a panasonic Js1f-b-12v-f relay on it. I need to change it but I only can find panasonic Js1-b-12v-f on the market. When I check the datasheet of both, I saw a ...
WhoCares's user avatar
1 vote
2 answers
182 views

Can a Float Valve Relay prevent Utility Sink Overflow?

A Samsung washing machine will empty into a utility sink that is outfitted with a drain pump. The purpose of the drain pump is to elevate the waste water into an existing drain pipe in the ceiling. ...
gatorback's user avatar
  • 3,088
3 votes
2 answers
388 views

Protecting Smoke Alarm Relay from Large (6.5 amp @ 120V) Inductive Load

We recently installed a whole house fan that has a max current of 6.5A at 120V. Due to the dangers of whole-house fans accelerating fires, we wanted to be safe and wire in a smoke alarm relay so that ...
thaimin's user avatar
  • 155
0 votes
2 answers
794 views

Wiring a 120 V device to a HVAC thermostat

I'm looking control a 120 V device with an HVAC thermostat. The device is a scrubber that cleans air and should\must only run when the HVAC is running (running in the cool state, heat state, or just ...
DDulla's user avatar
  • 101
0 votes
2 answers
2k views

Fridge Tripping GFCI but not when compressor is unplugged

I have a 12 year old GE Fridge in my garage that stopped freezing & cooling a few weeks ago. I diagnosed it as a bad relay and replaced it. Things ran normally for about 2 weeks and then one day ...
Mike's user avatar
  • 1
0 votes
0 answers
168 views

On-Delay, Under and Overvoltage Relay, Contactors AC-7a & AC-7b, Relay - Contactor compatibility, RCCB rated current higher than operational current

Background I live in Indonesia, the voltage for residential buildings ranges from 220 V to 230 V, I need help with the installation of the Schneider products. Here is the link to the thread about the ...
Daniel Denny Dillan's user avatar
0 votes
0 answers
58 views

How do I connect to C230B contactor?

I bought a contactor to wire a rely from 110V to 240V sauna heater. What kind of connector do I need to connect to the terminal? There is no documentation at all.
cuteCAT's user avatar
  • 139
0 votes
2 answers
462 views

2 wire thermostat, control relay

I currently have a 750mv propane stove in my living room. It is connected to a battery powered Honeywell programmable thermostat with 2 wires. The thermostat supports AC and fan. I have in my living ...
Brian D.'s user avatar
  • 121
0 votes
1 answer
816 views

Electrical Wiring Shelly 1L Breaker Shared With Sockets

I have lighting/wall circuit which I didn't put in place so don't have definitive information on its layout so bear with me. I want to put the Shelly 1L into the circuit at the switch. What I know ...
Ben Swinburne's user avatar
1 vote
0 answers
530 views

Maytag MED3500FW0 help with diagnosing no heat

I have a hope that you'll be able to either confirm or refute my diagnosis. As a quick aside, I work in computer science and have a decent bit of electrical engineering experience, as well as ...
Hunter's user avatar
  • 21
0 votes
1 answer
274 views

How to create a C-Wire from Honeywell R8888A/B

So Ive been trying to install a new Honeywell wi-fi thermostat. I have been unsuccessful in any event. I have a third wire unused at every thermostat in my home which is black. This black wire tuns ...
Nino Prainito's user avatar
1 vote
2 answers
469 views

Pigtail Line Side of GFCI

Is it O.K. to put a pigtail on the line side of an outdoor GFCI to power an irrigation pump (via relay)? The outlet would be used for the irrigation controller and misc. outdoor electrical items. The ...
Louis's user avatar
  • 79
0 votes
4 answers
248 views

Powering single HVAC damper from 3 circuits

I am updating a 1993 house in Texas and now have exhaust fans going through the roof, so I am also adding a fresh exterior air intake to the HVAC return plenum for make-up air. I want to open the ...
Kristen H's user avatar
0 votes
4 answers
1k views

Wiring an inverter into an RV using an contactor (AC Relay)

I am working on installing a DC to AC inverter (Victron Energy Phoenix 800VA) in my little teardrop RV such that the Inverter powers ALL the AC ports when it is turned on. The objective is to have it ...
Sam Carleton's user avatar
0 votes
0 answers
67 views

Refrigerator Compressor not working?

I unplugged then plugged back in my fridge an it isn't cooling or freezing! Does that mean my compressor is no more working? The light comes on inside the icebox?? Just not cooling or freezing..
Kimisha Stewart's user avatar
0 votes
2 answers
2k views

Circuit design for my sprinkler system

Basically, Installing a pump start relay into my system. Would like to run 6 #12AWG THHN wires through a carflex 1/2 conduit, from pump pressure switch, (under house, crawspace)area, up to 4"x4&...
bill's user avatar
  • 15
0 votes
3 answers
9k views

AC blower unit stops working intermittent

Recently my central AC's blower unit stops working intermittently after its been on for a few days with no issues. When it stops working, I will wait a few hours and then turn on the thermostat to AC ...
Da P.A's user avatar
  • 167