RIB current sensing relay on ECM circ

hot_rod

I bought this RIB from SupplyHouse.com, to see if it would work down on the low current draw of an ECM.

So when the pump boots up, starts spinning it makes a dry contact, by sensing the current. The line wrapped around the loop twice. This could fire a boiler, HP etc. Something to consider for TRV systems to wake up the boiler as flow starts moving. So no central t-stat needed to start the boiler.

It works on the 15-58 without any problem. It needed some adjusting to work on the Alpha ECM at low speed.

I tried the Phenix brand, an import knock-off, but it was fickle on the low ECM speeds. This one seems rock solid. I have it triggering a standard Caleffi ZVC t-stat connection, 24V.

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JDHW

The newer grundfos pumps UPS3 in the uk have pwm inputs and outputs. The output is related to the power consumption of the pump or fault conditions. Some sort of relay with a setpoint voltage could provide this functionality.

John

Derheatmeister

Nice…In europe the control strategy is somewhat reversed to this thought process.

1.Outdoor temp drops say below 58 F

2. Outdoor sensor communicates this with the boilers Control which allows the boiler and the Circulating pump to operate (Most Contractors here in the US just adjust this to 70F to be safe which increases the annual fuel comsumption)

3. Boiler »»»MODULATES«««on a curve based on the outdoor sensor readings which is justified since the OD temperature is causing the building to loose heat !

4. Older systems had a System circ which had a bypass…As most know the Newer"A" rated circs can »»»MODULATE««« based on a Delta P (TRV System) ,Delta t, combination thereof or a external signal such as a 0 VDC to 10 VDC signal which can come from the boiler control or in some cases it may even come from a Bacnet or a Solar control / Heat pump Control .

4. In europe we consider TRV'S as »»» "MODULATING "««« heat restricting Valves"««« Not activating Valves such as we install here in the US.

5. When the "Heat restrictive MODULATING valves proportionaly close based on the indoor temperature influences the system/Boiler circ "Sees" this restriction/reduction and MODULATES down.

Alot of energy saving MODULATING going on in europe.

Not sure if i will ever need to activate a boiler based on a circ command but i will keep this in mind .😉.

hot_rod

yes that makes good sense as a control strategy

ODR didn’t really take off here until tekmar started promoting it with mixing options. So older cast boiler systems would need that added.

I hope all is well with you and your growing family

Ironman

Just like we used to do with the old analog amprobes if the current draw was too low for the scale to properly sense it: wrap the wire around it ten times then divide the reading by 10. 😊

Kaos

Another option is a RIB2401D or RIBU1SC.. Very handy part to keep in your toolbox. Input can be either 120 or 24 and dry contact outputs.

offdutytech

Used those all the time in building automation systems. Check out Veris current sensors as well. They have ones with dry contacts and transducers to send out 0-10VDC or 4-20mA signals.