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Looking for a solid state relay with transformer similar to Honeywell RT850

Jells
Jells Member Posts: 576

I was delighted to find the RT850 unit to use for switching a Taco 006 circulator. It's current rating was higher than needed because it seems designed for resistive heating, but it was a nice simple package. Unfortunately it doesn't come in 120v! I can get it without the transformer, but that's not nice and neat. Does anyone know of a similar unit?

Comments

  • Big Ed_4
    Big Ed_4 Member Posts: 2,915
    edited June 17

    Make it simple , use a switching relay …

    There was an error rendering this rich post.

  • Jells
    Jells Member Posts: 576

    The one I have is very noisy. It's a small apartment and the idea of the quiet solid state seemed appealing as I was needing to replace it to get a C wire anyway.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,049
    edited June 15

    @Jells

    OONO F-1057 Looks like it will work. Contacts are rated 22 amps (resistive I think) 120-24 volt transformer built in and you can get a C wire off it. Less than $30 Don't know if it is SS but you won't be able to here it.

  • mattmia2
    mattmia2 Member Posts: 10,320

    This style of relay won't be silent but it will be quiet, it won't be anywhere near as loud as the relays used on a fan center:
    https://www.supplyhouse.com/White-Rodgers-90-293Q-Fan-Relay-Type-84-24-VAC-Coil-SPDT-Coil-Data-90-Ohms-DC-Resistance-125-mA-Nominal-3-VA-Nominal-4-VA-Inrush

  • Jells
    Jells Member Posts: 576

    Thanks. Will it be quieter than the Honeywell RA832A I pulled? What's the essential difference? I'd have to find a box to put that and a transformer in.

    I was looking at SS relays on Amazon, and they're similarly priced for the load we're talking about. The Taco 006 is only like 0.5A. Generally they're DC on the signal side, so I'd have to convert the 24VAC to DC for it. I've built these AC-DC myself many time for motor controls, just a bridge rectifier and a big electrolytic capacitor. So I'd need to put the relay, transformer and a AC-DC converter into a box. Is there's something I'm missing?

    ,

  • Jells
    Jells Member Posts: 576
    edited June 15

    Looks good, but why do you say I won't hear it? If it's mechanical it clicks, right? I've used the Taco pumps with the built in thermostat circuit, presumably they have a mechanical relay, and while I can hear them click, it's nowhere near as loud as the Honeywell RA832A.

  • mattmia2
    mattmia2 Member Posts: 10,320
    edited June 15

    probably don't need to filter it if you're just triggering a relay. there are ss relays with ac trigger ratings. look in the mouser or digikey catalog.

    you can get a transformer that mounts in a knockout.. you can use a 4" square or 4 11/16 box to mount the relay in. you can also get a TIB brand relay that mounts in a knockout. you need to look at the horsepower rating of the relay and the circulator motor because there is an inrush involved when the motor starts.

    you could also keep the honewell control in place and just use its transformer and a separate relay. the built in relay is probably rated 1/2 hp or more to control 3 piece circulators and oil burners, it needs more opening and closing force to deal with the higher power.

  • Jells
    Jells Member Posts: 576

    The ones I saw were all DC in the lower voltages, AC was 80v and more. The old relay unit doesn't have a C wire, so without hacking and soldering one in that won't work. For $30 I should probably check out the OONO F-1057. if it's quiet then I win a round finally.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,049
    edited June 16

    That relay has a transformer in it. What do you need another transformer for

    These relays are like a Rib relay, and you can't hear those pull in.

  • 109A_5
    109A_5 Member Posts: 1,388
    edited June 17

    Hello Jells,

    So you want a Solid State Relay with120 VAC control of a 120 VAC load ? Maybe try this;

    Mouser #: 576-SIR2B20A4

    Mfr. #: SIR2B20A4

    Mfr.: Littelfuse
    Description: Solid State Relays - Industrial Mount SOLID STATE RELAY-ISOLATED
    Load Current Rating: 20 A
    Load Voltage Rating: 120 VAC
    Relay Contact Form: 1 Form A (SPST-NO)
    Output Type: Triac
    Control Voltage Range: 90 VAC to 150 VAC, 90 VDC to 150 VDC

    https://www.mouser.com/ProductDetail/Littelfuse/SIR2B20A4?qs=5aG0NVq1C4yHd71RFPaTXg%3D%3D

    If you are actually looking for 24 VAC control and 120 VAC load, maybe something like this;

    Mouser #: 881-SHC23A50
    Mfr. #: SHC23A50
    Mfr.: Teledyne Relays

    Description: Solid State Relays - Industrial Mount
    Output: 50A, 24-265VAC
    Control: 20-280VAC, 22-48VDC / Zero-cross / IP20 cover

    https://www.mouser.com/ProductDetail/Teledyne-Relays/SHC23A50?qs=sGAEpiMZZMu%252Bisyu8Ze4r4jWbPW6qzSMTp1GNUkPunIrbtLsJVO1WQ%3D%3D

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Jells
    Jells Member Posts: 576

    Thanks, but no, I want 24 VAC control of 120 VAC.

  • Jells
    Jells Member Posts: 576

    Sorry, which relays?? there's been a number discussed so that "that one" and "this one" I'm not able to follow. The Oono you suggested looks great, but there's few reviews, and one on Amazon says it failed in a month. That's not encouraging.

  • Matt_67
    Matt_67 Member Posts: 299

    Aube rc840t-120 might be what you are looking for.

  • Jells
    Jells Member Posts: 576

    That's exactly what I ordered off Amazon an hour ago. Hope it's quiet.

  • mattmia2
    mattmia2 Member Posts: 10,320

    if you do the same parametric search at mouser but with a 24v or 24vac trigger you'll find what you're looking for

  • mattmia2
    mattmia2 Member Posts: 10,320

    https://www.mouser.com/ProductDetail/Opto-22/Z240D10-17?qs=sGAEpiMZZMu%252Bisyu8Ze4r4jWbPW6qzSMQYAdlMA9H3KihTyjOASUlw%3D%3D

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,049

    i think the Aube is the same as the oonof-1027

  • Jells
    Jells Member Posts: 576

    Got the Aube rc840t-120 in, bench tested it and it's very nearly inaudible! Perfect. Thanks all!

  • Jells
    Jells Member Posts: 576

    Looks that way. Dunno. There's a whole lot of rebadging going on with these devices. That RT850 seems to have at least 3 badges. I'm ok paying $20 more for a device that seems to have more behind it.