Electrical

Electrical Questions? Ask an Electrician Online.

Ask an Expert,
Get an Answer ASAP!

Electrical

I have a digital temperature display on a solar hot water

Customer Question
system. The display was provided...
I have a digital temperature display on a solar hot water system. The display was provided with 10K ohm thermistors. I have two thermistors attached to the outflow pipe of the solar array. One sensor is for the solar controller and the other for the display. The sensor and read out are 100ft apart. I used a 4 conductor wire, 18ga with shielding, non-twisted. It is marked as "Alarm Cable." I thought with the long run, and a partial buried run in conduit with coaxial, that this shielded wire would be a good cable. The 4 conductor allowed me to run to both thermistors.When I hook up the digital readout, it indicates temperatures at the extreme high of its range, regardless of the real temperature of the thermistor. This indicates, essentially no resistance. However, my multimeter accurately shows the resistance of the thermistor and is correct for temp. Further experiments on the remaining 400ft of the alarm cable spool actually push the readout beyond it usable range on the high side, but resistance is correct on my multimeter. It is accurate and responsive as I can hold the thermistor and watch temp/resistance change. Similar experiments with 100ft of speaker cable and 200ft of thermostat wire produce similar results. Even in a shorter run, of 25ft, the alarm cable seems to raise the readout temp reading by a degree or two compared to resistance readings.The manufacturer recommends 20ga twisted pair wire for extending the probes up to "several hundred feet." The "Alarm Cable" appears non-twisted. Is this the issue, the linear non-twisted alarm cable is producing a weird reading just for the display? Or is the shielding a problem? It seems I have eliminated the shielding by trying other types of wire. The manufacturer did tell me thermostat wire does weird things for some reason. I can't understand why the resistance readings are correct, but the readout is effected somehow.What should I try next, two runs of 20ga twisted, non-shielded, or shielded. Can I get a 4 conductor cable with two twisted pairs, shielded, or unshielded.Thanks.
Submitted: 1 year ago.Category: Electrical
Show More
Show Less
Ask Your Own Electrical Question
Answered in 15 minutes by:
9/28/2016
Electrician: Rico Soma, Electrical Technician replied 1 year ago
Rico Soma
Rico Soma, Electrical Technician
Category: Electrical
Satisfied Customers: 23,041
Experience: Service Tech
Verified

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can continue our conversation.

I don't understand your readings either since we routinely use 18 ga solid (not stranded not shielded) cable and have never had an issue. Since the manufacturer recommends 20 ga stranded pair then you should go with that. 20 gauge stranded is used for speaker wire. However it and just about any 20 ga wire is not UV rated so it will break down in sunlight. So run it so it's not in the sun

Ask Your Own Electrical Question
Customer reply replied 1 year ago
Rick, thanks for the response. I can hide the wire, I have it all tidy in conduit. I run underground parallel to some coax, as I mounted my mini TV dish on the solar structure and not my house. It is a ground mount solar array for heating hot water. I don't understand the readings either. This is the second display, I thought perhaps the first one was damaged, or I damaged it, but I get the same exact readings. I guess seeing the temps is not all that important, it was more out of curiosity and tracking performance, but I want to know that the pump controller is getting the proper inputs from its thermistor. It also shows the correct resistance. It seems the non-twisted wire, despite showing the proper resistance, is getting an odd signal feeding back to the display.
Electrician: Rico Soma, Electrical Technician replied 1 year ago

I can't address the display readout anomaly. After you install the type of wire the manufacturer recommends, if you still have a problem then it sounds like a warranty issue that you need to take up with them. We use Resol controllers and haven't had any problems with them.

Ask Your Own Electrical Question
Customer reply replied 1 year ago
I will try some other wire. Can we forward this question to an electrical engineer somehow, seems like it is a conductance issue in the wire somehow.
Electrician: Rico Soma, Electrical Technician replied 1 year ago

We don't have an electrical engineering category only an electrical category where you'll get an electrician not an engineer. I can ask the mods to move it to electrical if you like.

Ask Your Own Electrical Question
Customer reply replied 1 year ago
lets get there take on it, I'm just perplexed it doesn't work.
Electrician: Rico Soma, Electrical Technician replied 1 year ago

Ok, please be patient it may take a while. Please don't respond until one of us gets back to you.

Ask Your Own Electrical Question
Electrician: JACUSTOMER-1eysp1u4-,
 replied 1 year ago
JACUSTOMER-1eysp1u4-
Category: Electrical
Satisfied Customers: 41
Experience: Journeyman Electrician, Lead Man (Sub-Foreman) at Romanoff Electric
Verified

Hello, Welcome to JA/Pearl my name is***** and I will try to assist you today.

I have the better part of 20 years as a commercial electrician and about a year of electronics engineering classes under my belt, and I 'll try to give you some insight with what I know of low voltage installations such as the one you have.

The likely cause of poor sensor operation is in most cases EMI noise on the line either end of the circuit could be contributing to it.( possibly the sensors themselves interfering with each other) Generally, in commercial buildings, to remove any form of EMI from the equation engineers spec twisted pair cable or twisted pair shielded cable to be installed properly by the contractor ( properly grounding the shield in one location as well as continuing the shield throughout the entire installation.

So to answer which is the best for your problem I would run the recommended #AWG from the manufacturer in a twisted / shielded solid conductor for a permanent installation or stranded if you feel the solid cable could become damaged. Multiple low voltage wire manufacturers on the market like Belden brand although they can be very expensive. I would definitely shop around.

Let me know if that answers you problem, this thread will remain open for some time, Please do not forget to rate me if you are satisfied with my answer. Thank you for using JA/Pearl , and have a wonderful day.

Ask Your Own Electrical Question
Ask JACUSTOMER-1eysp1u4- Your Own Question
JACUSTOMER-1eysp1u4-
JACUSTOMER-1eysp1u4-
JACUSTOMER-1eysp1u4-
Category: Electrical
Satisfied Customers: 41
41 Satisfied Customers
Experience: Journeyman Electrician, Lead Man (Sub-Foreman) at Romanoff Electric

JACUSTOMER-1eysp1u4- is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future.

JimmyBagley, IA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

Mike

Mike

Master Electrician

1,426 satisfied customers

Licensed Master Electrician - OnQ Certified Data Voice Audio Video Installer

Jason

Jason

Service Technician

3,942 satisfied customers

Over 20 years of experience in all types of installations, troubleshooting, and repairs.

Mike G.

Mike G.

Master Electrician

7,826 satisfied customers

Proven Professional 48 years Experience

Kevin

Kevin

Licensed Electrical Contractor

3,870 satisfied customers

31 years Licensed Electrical Contractor in Illinois, Adjunct College Electrical Instructor, Former Electrical Inspector, Diploma: Digital Electronics, FCC Technician License

AssuredElectrical

AssuredElectrical

Master Electrician

3,264 satisfied customers

Contractor-42+ Years in the ElectricalTrade

electrifier

electrifier

Master Electrician

1,458 satisfied customers

Electrical contractor and electrical inspector for over 24 years with phone and networking expertise

Rich

Rich

Master Electrician

1,115 satisfied customers

Over 35 years residential, commercial, industrial wiring, install, troubleshoot, service, maintain

< Previous | Next >

Related Electrical Questions
I have a low voltage transformer in my garage which has 4
I have a low voltage transformer in my garage which has 4 lines coming out of it and out of the house to power landscape lights, etc... we have two main path lights that are connected to this transfor… read more
Kevin
Kevin
Licensed Electrical Contractor
Diploma
3,870 satisfied customers
My outdoor post light has low voltage. It did work and then
My outdoor post light has low voltage. It did work and then stopped working, I changed out three bulbs and they will not come on. I put an led bulb in the lamp and get a weak glow. The incodesent bulb… read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
If you run 110volts through a low voltage high bay lite on
If you run 110volts through a low voltage high bay lite on accident will it fry the built in driver. … read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
Can I use a steel conduit lockout on pvc male adaptor into
Can I use a steel conduit lockout on pvc male adaptor into utility box on end of my pvc conduit?… read more
Kevin
Kevin
Licensed Electrical Contractor
Diploma
3,870 satisfied customers
Can I add a 90 elbow to the main conduit so that I can raise
can I add a 90 elbow to the main conduit so that I can raise that conduit the conduit is running vertical and i need some height under the conduit … read more
Kevin
Kevin
Licensed Electrical Contractor
Diploma
3,870 satisfied customers
There is a low voltage lighting circuit in my flat. Can I
There is a low voltage lighting circuit in my flat. Can I buy standard fittings and have them converted to plug into the LV circuit?… read more
Plumbers_Mate
Plumbers_Mate
General Manager
Vocational, Technical or Trade Scho
2 satisfied customers
Can you splice in outdoor string lights to a low voltage
Can you splice in outdoor string lights to a low voltage landscape system? … read more
Sam I
Sam I
Electrician
B.S.
473 satisfied customers
I have a kitchen with 8 low voltage (50W) recessed lights
I have a kitchen with 8 low voltage (50W) recessed lights around the perimeter ceiling. They have always burned out quickly, and all have been out for a long time now. Got tired of replacing them ever… read more
Kevin
Kevin
Licensed Electrical Contractor
Diploma
3,870 satisfied customers
I have low voltage between black aqnd wires when i chech
hi i have low voltage between black aqnd white wires when i chech between black and ground i get 120 v whats happening? … read more
Sam I
Sam I
Electrician
B.S.
473 satisfied customers
I have a dedicated 10 amp romex line in conduit, going to a
I have a dedicated 10 amp romex line in conduit, going to a direct wired garbage disposer under my kitchen sink. I want to connect this line up to a single gang outlet box to make exchanging the dispo… read more
Sam I
Sam I
Electrician
B.S.
473 satisfied customers
I am running 3 circuits inside of pvc conduit. 220v 30a
I am running 3 circuits inside of pvc conduit.220v 30a water heater 220v 15a ac 120v 20a receptaclecan I use 1 shared 10awg ground wire for all circuits?… read more
Mike G.
Mike G.
Master Electrician
Vocational, Technical or Trade Scho
7,826 satisfied customers
How much to install 100' of electrical line in a conduit if
how much to install 100' of electrical line in a conduit if the trench is already dug. Include the cost of wiring and adding a 50 Amp Circuit Breaker … read more
Kevin
Kevin
Licensed Electrical Contractor
Diploma
3,870 satisfied customers
Topic is low voltage landscape lighting. It appears that
Good Evening - Topic is low voltage landscape lighting. It appears that several lines do have power while other do not. For the lines that have no power, I have checked the following – • Light bulbs h… read more
Mike G.
Mike G.
Master Electrician
Vocational, Technical or Trade Scho
7,826 satisfied customers
What size wire is needed to run underground in conduit to a
What size wire is needed to run underground in conduit to a garage about 60 feet from the main connection at the power pole? This would be connected to a subpanel in the garage. … read more
Kevin
Kevin
Licensed Electrical Contractor
Diploma
3,870 satisfied customers
Do you need to remove existing conduit and or conductors if
Do you need to remove existing conduit and or conductors if they are being abandoned and not being used? … read more
Mike G.
Mike G.
Master Electrician
Vocational, Technical or Trade Scho
7,826 satisfied customers
I have a string of low voltage ikea Xmas led lights. I want
I have a string of low voltage ikea Xmas led lights. I want to connect them to my low voltage landscape lights. I have stripped the Xmas wires and connected them to my landscape lights. But they do no… read more
George Smith
George Smith
Vocational, Technical or Trade School
317 satisfied customers
I have low voltage (12V) suspended track lighting. The old
I have low voltage (12V) suspended track lighting. The old transformer died. I got a replacement 120V step down to 12V with a 150 Watt max. I tested the load which measured 120V. After connecting the … read more
James I
James I
Pool Plant Operator
21 satisfied customers
I need to know if this timer is workable with a low voltage
I need to know if this timer is workable with a low voltage fireplace switch. There are 2 wires, as pictured, black and red. No ground.https://smile.amazon.com/Skytech-Fireplace-Control-Wireless-Mount… read more
George Smith
George Smith
Vocational, Technical or Trade School
317 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x