Help with a simple wiring diagram

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JoeNorm

Senior Member
Location
WA
I am installing a spot ERV, much like a fan.

I am not too familiar with wiring diagrams but this one is pretty simple. Looks like unit gets wired direct to power than there are other wires run for switching.

My question is what wire would you use for the switch portion? I could use 14-3 but I am wondering if there is something more appropriate here. See link to diagram.


Thanks!
 

Ainsley Whyte

Senior Member
Location
Jamaica
Occupation
Senior Electrical Engineer
I am installing a spot ERV, much like a fan.

I am not too familiar with wiring diagrams but this one is pretty simple. Looks like unit gets wired direct to power than there are other wires run for switching.

My question is what wire would you use for the switch portion? I could use 14-3 but I am wondering if there is something more appropriate here. See link to diagram.


Thanks!
1582984818269.png

My friend look at the diagram main switch is in series with Live wire as shown just a matter of switching on and off the power
Hope i understand you correctly.
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
The two switches for selecting standby and Hi/Lo fan speed go to the control board only, and so I suspect they are very low power, but I didn't see anything specific in the spec sheets about this. The maximum fan power is 24 watts and it's supplied through the separate L-N terminals as in the schematic above. So 14 AWG is certainly adequate for the switch wiring.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
It appears to already have a switch for the main. You don't need to do anything with the yellow, orange, and blue wires, those are control wires already in the assembly. If you wanted to add a main switch, just wire your hot/black line wire to a switch. But this looks unnecessary since it appears to already have a main.
 

kwired

Electron manager
Location
NE Nebraska
Could just install appropriate jumpers if you will never change CFM and put switch in supply line if desired to have a wall control.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
My question is what wire would you use for the switch portion? I could use 14-3 but I am wondering if there is something more appropriate here. See link to diagram.
This depends more on the physical requirements of the environment more than on the electrical needs.

What wiring methods are appropriate for the space where the wiring will be run? In wall or exposed, etc?
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
I didn’t look good, but is the control wiring 120v? I know the source wiring is..
I don’t know what’s on the back side of that circuit board..
If it isn’t just use thermostat wire
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
He doesn't need any control wiring. It shows all that self-contained. Only thing needed is power to the switch, which shows is also present. As I said earlier, you could add another main switch if you want.
 

controlled

Senior Member
He doesn't need any control wiring. It shows all that self-contained. Only thing needed is power to the switch, which shows is also present. As I said earlier, you could add another main switch if you want.
Its not all self contained. The hi/low , and standby shows as being a wall switch. Typically thay would be 24 volt, but i dont see a transforer on the schematic. Looks like line voltage to a pair of switches. I would run 14/3 from unit to switch box and install a double switch
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Its not all self contained. The hi/low , and standby shows as being a wall switch. Typically thay would be 24 volt, but i dont see a transforer on the schematic. Looks like line voltage to a pair of switches. I would run 14/3 from unit to switch box and install a double switch
That’s what I was stating regarding not being able to see the back side of the circuit board. An XF or SMPS could be back there for all we know.
 

JoeNorm

Senior Member
Location
WA
Yes, they sell a double switch for this which I have.

The idea is that the main switch is On/Off and the second switch will do Hi/Low
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Its not all self contained. The hi/low , and standby shows as being a wall switch. Typically thay would be 24 volt, but i dont see a transforer on the schematic. Looks like line voltage to a pair of switches. I would run 14/3 from unit to switch box and install a double switch
🤬 Guess I need new glasses, I did not notice it said wall switch. But I was mainly looking at the PDF the OP posted a link to.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Its not all self contained. The hi/low , and standby shows as being a wall switch. Typically thay would be 24 volt, but i dont see a transforer on the schematic. Looks like line voltage to a pair of switches. I would run 14/3 from unit to switch box and install a double switch

You wouldn't see a transformer in that wiring diagram if it's on the PC board. So we don't know. What does the instructions say for that wiring? Line voltage or LV?

If in doubt use 14/3 NM.

-Hal
 
Product install manual, wiring diagram, promotional materials, and specs mention nothing about low voltage. Everything says 120v

From their promotional brochure...

“Wiring
Power consumption is 23 Watts at 40 CFM with a power rating of 120/60 V/Hz. Bring house power to the unit junction box and use 3 wires to connect the 2 switches.”

Using that I would suggest using whatever is rated for 120v to be used with your specific application. As Larry has mentioned, it will depend on your job site requirements, but looks like you should be using 14/3 for whatever type wire you use.

Sent from my iPhone using Tapatalk
 
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