u/FoldedKettleChips

Hey All,

I want to make sure that my wiring strategy is correct before I install a heat pump outdoor unit (ODU). My goal is to monitor power consumption at my heat pump outdoor unit and to monitor temperature at the liquid line, suction line, and outdoor ambient condition.

I intend to use a Shelly EM Gen 3 to monitor power and a Shelly Plus Add On for the sensors. Since I would like to keep the sensor wiring short, I would like to locate the EM inside the actual outdoor unit. The heat pump outdoor unit requires a 240V circuit, the MCA is 17.4, and the MOP is 20. The wiring run is about 20' total from my panel to the ODU so I was considering 12 AWG wire but I'm planning to install 10 AWG just in case a future heat pump might draw more amperage.

Here's my wiring plan:

• Run 10 AWG from a two pole 20A breaker to a disconnect box.
• Disconnect box is the Rectorseal RSH-50 VRMDC with surge protection, voltage monitoring, and 60A disconnect.
• Run 10 AWG in liquid tight from the disconnect box to the outdoor unit.
• Once inside the outdoor unit, connect the 10 AWG to two Wago 221-613s.
• Out of the Wagos, continue the 10 AWG to the L1 and L2 terminals on the heat pump.
• Out of the Wagos, run 12 AWG into a smaller NEMA project box to power the Shelly EM Gen3.
• Clamp the Shelly CT around the 10 AWG feeding either L1 or L2.
• Clip the Add-On to the EM and run the sensors out of the box.
• Leave the small NEMA project box inside the ODU wiring compartment.

Are there any issues with the wiring diagram below that anyone sees?

https://preview.redd.it/n5wro5th3b2h1.png?width=1093&format=png&auto=webp&s=45903c43768932df8b1efb54c272fcc0b1f2e082

Hey All,

I want to make sure that my wiring strategy is correct before I install a heat pump outdoor unit (ODU). My goal is to monitor power consumption at my heat pump outdoor unit and to monitor temperature at the liquid line, suction line, and outdoor ambient condition.

I intend to use a Shelly EM Gen 3 to monitor power and a Shelly Plus Add On for the sensors. Since I would like to keep the sensor wiring short, I would like to locate the EM inside the actual outdoor unit. The heat pump outdoor unit requires a 240V circuit, the MCA is 17.4, and the MOP is 20. The wiring run is about 20' total from my panel to the ODU so I was considering 12 AWG wire but I'm planning to install 10 AWG just in case a future heat pump might draw more amperage.

Here's my wiring plan:

• Run 10 AWG from a two pole 20A breaker to a disconnect box.
• Disconnect box is the Rectorseal RSH-50 VRMDC with surge protection, voltage monitoring, and 60A disconnect.
• Run 10 AWG in liquid tight from the disconnect box to the outdoor unit.
• Once inside the outdoor unit, connect the 10 AWG to two Wago 221-613s.
• Out of the Wagos, continue the 10 AWG to the L1 and L2 terminals on the heat pump.
• Out of the Wagos, run 12 AWG into a smaller NEMA project box to power the Shelly EM Gen3.
• Clamp the Shelly CT around the 10 AWG feeding either L1 or L2.
• Clip the Add-On to the EM and run the sensors out of the box.
• Leave the small NEMA project box inside the ODU wiring compartment.

Here are my questions:

• Are there any glaring issues that anyone sees with this plan?
• Are there any code issues that anyone foresees?
• I will have 240V power in the NEMA box but also some low voltage sensors. Does NEC 725.136(D) allow this?

https://preview.redd.it/ap5vh4aa3b2h1.png?width=1093&format=png&auto=webp&s=9e8b1517140ca9afd36079c4fe57a9c11fe22f96

Hey All,

I want to make sure that my wiring strategy is correct. My goal is to monitor power consumption at my heat pump outdoor unit and to monitor temperature at the liquid line, suction line, and outdoor ambient condition.

I intend to use a Shelly EM Gen 3 to monitor power and a Shelly Plus Add On for the sensors. Since I would like to keep the sensor wiring short, I would like to locate the EM inside the actual outdoor unit. The heat pump outdoor unit requires a 240V circuit, the MCA is 17.4, and the MOP is 20.

Here's my wiring plan:

• Run 10 AWG from a two pole 20A breaker to a disconnect box and then on to the heat pump.
• Connect the 10 AWG to two Wago 221-613s.
• Continue the 10 AWG to the L1 and L2 terminals on the heat pump.
• Splice 12 AWG into a smaller NEMA project box to L & N on the Shelly EM Gen3.
• Clamp the CT around the 10AWG feeding either L1 or L2 and terminate into IA.
• Clip the Add-On to the EM and run the sensors out of the box.

Here are my questions:

• Is this the correct or preferred way to wire the EM?
• Are there any code issues that anyone foresees?

https://preview.redd.it/x6figc411b2h1.png?width=1091&format=png&auto=webp&s=bb83ab7f6f2c4a9c0f58e6d2540cf91ef7a599d2

Hello! I am looking to set up a smart control arrangement for my Energy Recovery Ventilator. I am looking to monitor energy usage, turn the ERV on an off (put it in standby mode), and set it to boost (run at a higher flow rate) based on air quality monitors that I'll connect through Home Assistant. Since I am looking to achieve three main control functions, I am looking at installing three Shelly devices.

The Panasonic ERV I have is the FV-15ESC1 and it includes dry contacts that put the unit into standby and boost.

I was looking at the Shelly EM Mini Gen4 for Power Monitoring and two Shelly 1 Gen4s to control the dry contact functions on the ERV. Here is the install guide: 15ESC1450_english_ final editable. I also pasted a picture of the dry contact wiring diagram from the guide and the PCB diagram from the guide.

To keep everything essentially in the same junction box and to avoid transformers, I was going to bring a 120V AC circuit into the junction box and power all of the Shelly devices via that circuit. Then power the ERV from that circuit as well.

I dont know if there is a strong advantage to using a power source other than the 120V AC powering the ERV.

My understanding of from looking into the NEC is I can keep the dry contact wiring in the same junction box as the line voltage wiring as long as I use wiring with insulation that's rated for line voltage. I was going to use 14ga THHN for everything anyway.

Can anyone let me know if you see any glaring issues with my plan? Or if there is a simpler way to achieve my goals?

Here's My Proposed Wiring Diagram

Here are the control wiring methods from the install guide

Here's the wiring diagram of the PCB from the install guide

Hello, I am looking to set up a smart control arrangement for my Energy Recovery Ventilator. I am looking to monitor energy usage, turn the ERV on an off (put it in standby mode), and set it to boost (run at a higher flow rate) based on air quality monitors that I'll connect through Home Assistant. Since I am looking to achieve three main control functions, I am looking at installing three Shelly devices.

The Panasonic ERV I have is the FV-15ESC1 and it includes dry contacts that put the unit into standby and boost.

I was looking at the Shelly EM Mini Gen4 for Power Monitoring and two Shelly 1 Gen4s to control the dry contact functions on the ERV. Here is the install guide: 15ESC1450_english_ final editable. I also pasted a picture of the dry contact wiring diagram from the guide and the PCB diagram from the guide.

To keep everything essentially in the same junction box and to avoid transformers, I was going to bring a 120V AC circuit into the junction box and power all of the Shelly devices via that circuit. Then power the ERV from that circuit as well.

I dont know if there is a strong advantage to using a power source other than the 120V AC powering the ERV.

I also have looked at the NEC and it seems like I can keep the dry contact wiring in the same junction box as the line voltage wiring as long as I use wiring with insulation that's rated for line voltage. I was going to use 14ga THHN for everything anyway.

Can anyone let me know if you see any glaring issues with my plan? Or if there is a simpler way to achieve my goals?

Proposed Wiring Diagram

Main PCB From Install Guide

Control Wiring Methods From Install Guide