Can I mix AWG for a COB fixture if I am running wire 10 feet?

I am planning on having a long-ish cable run (10ft or so) of 16 AWG from the drivers to the COBs. At the drivers, I would use 18 AWG to connect them to each other in series and then at the last COB, connect back to the 16 AWG wire I set out at the beginning.

Is this safe?

Thanks. I'm just paranoid about electrical work. Paranoia is good, sometimes..

what kind of driver. you need to account for voltage drop in any long run.

Thanks. The driver is HLG 120H C1400B. Circuit is 100V, approximately 150W max.

Also, separately there will be a similar, shorter run for 3x HLG 185H C700B. I was going to run 16 AWG about 7-8' to the ceiling and then use 18 AWG to connect the COBs to each other.

These would be the higher Voltage circuits. Each one is running about 280V.

for 1400 mA at high voltage 16 GA would be fine.

if it was 16A at 48V id say differently

drop is based on current and distance and is independent of voltage.

at only 1.4A over 10 feet:

20 ga 0.28V
18 ga 0.17V
16 ga 0.11V
14 ga 0.07V

most of which are negligible for your 280V circui

16A at 10 feet
20 ga 3.24V
18 ga 2.03V
16 ga 1.28V
14 ga 0.80V

all of which are significant when youre only working with 36-50V to begin with. youre dropping 1-2V per cob vs dropping 0.2A overall with high voltage low current wiring

obviously 16A is a massive load thats an HLG600-36B with all the power pushed thru one set of conductors.

if youre going to remote driver cobs wired in series its just as well to run individual cables
take that 16A thru 8 pieces of 18-2 Tstat wire over 10 feet and the effective current per cable is only 2A and the drop is only 0.25V

miggaman said:

I am planning on having a long-ish cable run (10ft or so) of 16 AWG from the drivers to the COBs. At the drivers, I would use 18 AWG to connect them to each other in series and then at the last COB, connect back to the 16 AWG wire I set out at the beginning.

Is this safe?

Thanks. I'm just paranoid about electrical work. Paranoia is good, sometimes..

Click to expand...

I would normally not recommend changing wire sizes unless the smaller wire has less current going through it and that does not appear to be the case here. BUT - you are only running 1.4 Amps through it so 18 AWG is plenty big enough for that amount of current.

18 gauge should work fine for your runs they are dc volts and drops will not be significant

VegasWinner said:

18 gauge should work fine for your runs they are dc volts and drops will not be significant

Click to expand...

fun fact: AC and DC currents size conductors identically, DC circuits just happen to be lower amperage in most cases (not that 16A one I described, thats more like car battery charger currents and you know how big those cables are typically)

CobKits said:

fun fact: AC and DC currents size conductors identically, DC circuits just happen to be lower amperage in most cases (not that 16A one I described, thats more like car battery charger currents and you know how big those cables are typically)

Click to expand...

It is amps that kill not volts. Most of the circuitry carries low voltage and amps dependent on drivers. A 2100mA driver is carrying 2 amps, not much current, low in power due to low DC voltage. I have worked on HF, UHF, VHF, etc radio systems using 24v and megaAmps with high power antennae. 16-18 gauge wire on average throughout, except devices meant to carry large current loads, solid copper. Most logic circuitry can be 22 gauge 5v-12v, low power 22-18 gauge, medium power 14-16 gauge

If you are concerned with power loss or resistance, you can use solid conductor vs. twisted conductors. most lights folks are concerned with can work with 18 gauge for cabling and even 22 gauge for cob wiring internally.

VegasWinner said:

It is amps that kill not volts. Most of the circuitry carries low voltage and amps dependent on drivers. A 2100mA driver is carrying 2 amps, not much current, low in power due to low DC voltage. I have worked on HF, UHF, VHF, etc radio systems using 24v and megaAmps with high power antennae. 16-18 gauge wire on average throughout, except devices meant to carry large current loads, solid copper. Most logic circuitry can be 22 gauge 5v-12v, low power 22-18 gauge, medium power 14-16 gauge

If you are concerned with power loss or resistance, you can use solid conductor vs. twisted conductors. most lights folks are concerned with can work with 18 gauge for cabling and even 22 gauge for cob wiring internally.

Click to expand...

This is mostly true, but since you've worked on high power transmitters (I have as well, but on radar equipment for the Navy). Then you also know that the higher the voltage is, your skin presents lower resistance to it as the voltage increases (especially if it is wet).

I just don't want someone who knows next to nothing about electricity to read your post and think just because it's [email protected] or 2.1A that it can't kill you, because it can. You should always respect the potential of electricity, no matter the voltage or amplitude.

De-rate your conductors, I wouldn't use thermostat wire, since it isn't for use in this type of application, like at all.

Stranded wire of the appropriate type is better for almost every application related to gardening because we move things around. Unless it is going to be installed somewhere permanently (like on a fixture) then sometimes solid conductors are better, if they aren't subject to any sort of strain and don't get moved frequently. Copper work hardens quickly and will crack over time if subjected to strain in the same place repeatedly.

Thanks everyone for your input! I am so glad I can ask my questions and they will get answered by people with expertise and experience!

Stay Lit,
Miggaman

dstroy said:

This is mostly true, but since you've worked on high power transmitters (I have as well, but on radar equipment for the Navy). Then you also know that the higher the voltage is, your skin presents lower resistance to it as the voltage increases (especially if it is wet).

I just don't want someone who knows next to nothing about electricity to read your post and think just because it's [email protected] or 2.1A that it can't kill you, because it can. You should always respect the potential of electricity, no matter the voltage or amplitude.

De-rate your conductors, I wouldn't use thermostat wire, since it isn't for use in this type of application, like at all.

Stranded wire of the appropriate type is better for almost every application related to gardening because we move things around. Unless it is going to be installed somewhere permanently (like on a fixture) then sometimes solid conductors are better, if they aren't subject to any sort of strain and don't get moved frequently. Copper work hardens quickly and will crack over time if subjected to strain in the same place repeatedly.

Click to expand...

security wire two conductor works great too stranded. I know amps kill. I got hit with an RF burn that should have killed me in Vietnam. I was tuning antennae blades on an HF radio, when someone bumped me and I touched a blade and sent high current transmit quality thru my finger to ground, shot me in the air three feet, with a repeat before someone pushed me off the rig. Blew out my second finger left hand, it took years before that finger looked regular again. I used to work in low and high power as electrician many years ago. I also worked in a recording studio as a sound engineer assistant , the key is grounding at all times while you work and equipment grounding. A ground clip always works while working.

dstroy said:

This is mostly true, but since you've worked on high power transmitters (I have as well, but on radar equipment for the Navy). Then you also know that the higher the voltage is, your skin presents lower resistance to it as the voltage increases (especially if it is wet).

I just don't want someone who knows next to nothing about electricity to read your post and think just because it's [email protected] or 2.1A that it can't kill you, because it can. You should always respect the potential of electricity, no matter the voltage or amplitude.

De-rate your conductors, I wouldn't use thermostat wire, since it isn't for use in this type of application, like at all.

Stranded wire of the appropriate type is better for almost every application related to gardening because we move things around. Unless it is going to be installed somewhere permanently (like on a fixture) then sometimes solid conductors are better, if they aren't subject to any sort of strain and don't get moved frequently. Copper work hardens quickly and will crack over time if subjected to strain in the same place repeatedly.

Click to expand...

It should be noted that it takes a surprisingly small amount of current to kill you - 100 mA is generally considered potentially lethal.

100mA across the heart can kill, just needs the Voltage to move it

Solid core sucks, in nearly every application that isn't set it and forget it imo, I'll always look for a stranded solution.

dstroy said:

De-rate your conductors, I wouldn't use thermostat wire, since it isn't for use in this type of application, like at all.

Click to expand...

CMR 18/2 cable is good for 300V and 5A or more. not sure how you can say its not acceptable for our application

CannaBruh said:

100mA across the heart can kill, just needs the Voltage to move it

Click to expand...

Yup, and under the right conditions, that can be as low as 30 volts.

remember that voltage is basically potential.

falling out of an airplane wont kill you but that landing is a bitch.

CobKits said:

remember that voltage is basically potential.

falling out of an airplane wont kill you but that landing is a bitch.

Click to expand...

Yup and its the ground that gets you in both instances.

ESD is many volts, no dead humans but RIP sand critters

Some potential has to be reached to conduct and there has to be ample current supplied to do damage... if your skin is of low enough resistance with a high enough "potential" and enough juice "flow" danger danger

Touch the terminals of a car batter, lots of amps but lots of ohms