Use the calculator with exact cable and installation assumptions whenever possible. The result connects voltage drop, delivered power and thermal risk so engineering and procurement can compare Cat5e, Cat6, Cat6A, solid copper, stranded copper and CCA options on the same basis.
How to interpret PoE voltage drop and cable temperature
A useful PoE cable decision combines the powered-device load, PSE voltage, conductor resistance, channel length, number of energized pairs, connectors, ambient temperature and bundle size. Cable category alone does not determine whether a link can safely support IEEE 802.3af, 802.3at or 802.3bt.
Engineering rule: use the calculator as a preliminary design check, then verify the result against the exact cable data sheet, device input range, connector ratings, applicable cabling standard and local installation requirements.
Voltage drop
Approximate cable drop with V = I × R. Use the effective loop resistance after accounting for parallel conductors and the active PoE pair sets.
Cable heat
Conductor loss follows P = I2R. Higher current, thinner conductors, CCA material and elevated temperature all reduce margin.
Bundle conditions
A large, tight bundle traps heat. Conduit fill, ceiling temperature, ventilation and the number of simultaneously powered cables matter.
End-to-end channel
Include horizontal cable, patch cords, connectors and connection points. A 100-meter channel is not electrically identical to 100 meters of one cable type.
24AWG vs 26AWG PoE and CAT6A high power PoE selection
For the same conductor material and length, a lower AWG number means a larger conductor and lower resistance. That is why 23AWG or 24AWG solid copper is normally preferred for long, high-power links, while 26AWG and 28AWG constructions are better reserved for short, specifically rated patch cords.
| Cable option | Typical PoE use | Main engineering concern | Selection direction |
|---|---|---|---|
| 23AWG CAT6 / CAT6A solid copper | Long runs, PoE++, access points and lighting | Bundle temperature and pathway design still need review | Strong default where electrical and thermal margin matters |
| 24AWG CAT6 solid copper | Many conventional PoE and some qualified PoE++ channels | Check resistance, device power, length and bundle size | Accept when the full channel calculation and product rating pass |
| 26AWG patch cable | Short equipment and rack connections | Higher resistance than 23/24AWG | Use only within the cord maker's PoE and length limits |
| 28AWG patch cord | Very short, high-density patching | Highest resistance and heat concentration in this comparison | Require an explicit PoE++ rating and strict length/bundle control |
| CCA cable | Not recommended for standards-based PoE channels | Higher resistance, greater voltage drop and more heating | Specify solid bare copper conductors |
When reviewing 802.3bt cable selection, confirm four-pair operation and the real channel resistance rather than relying on the CAT6 or CAT6A label. A PoE++ cable calculator is most useful when its current, conductor, temperature and distance assumptions match the proposed installation.
PoE camera cable distance and PoE lighting cable design
For cameras, the question is not only whether Ethernet data reaches 100 meters. The remaining voltage at the powered device must stay above its input minimum during peak load, startup, heater operation and night-time IR illumination. Use the PoE voltage drop calculator with measured or worst-case camera power, then compare the estimated PD voltage with the camera data sheet.
PoE lighting is a continuous-load, often high-density application. Start with solid-copper 23AWG CAT6 or CAT6A, then check bundle size, ceiling or conduit temperature, cable temperature rating and connector compatibility. Segmenting large bundles and improving airflow can be as important as changing category.
CAT6 PoE voltage drop
Use verified DC resistance and complete channel length; CAT6 products can use different conductor gauges.
PoE cable temperature rise
Estimate I2R loss, then assess ambient temperature, bundle density and heat dissipation.
CCA cable PoE voltage drop
Expect more resistance and heat than solid copper of comparable nominal size.
CAT6A high power PoE
Often provides better conductor and thermal margin for 802.3bt, large bundles and demanding endpoints.
PoE voltage drop and cable selection FAQ
How much voltage drop occurs over 100 meters of CAT6?
It depends on conductor resistance, current, pair usage and temperature. As an illustrative case, a 23AWG solid-copper conductor near 6.7 Ω/100 m produces an effective PoE loop near 6.7 Ω when each polarity uses two parallel conductors; at 0.6 A, the cable drop is about 4.0 V. Use the exact data-sheet resistance and calculator inputs for the real channel.
Can a 24AWG CAT6 cable support PoE++?
Yes, when it is a standards-compliant four-pair channel and its resistance, length, connectors, ambient temperature and bundle conditions remain within rating. For long or heavily bundled high-power links, 23AWG solid copper usually offers more margin.
Is 26AWG patch cable suitable for IEEE 802.3bt?
A compliant 26AWG patch cord can be suitable for a short connection within its manufacturer's PoE rating and channel rules. Do not use it as a substitute for a 90-meter solid-copper horizontal cable.
Does CCA cable cause more PoE voltage drop?
Yes. CCA normally has higher resistance than solid copper of the same nominal gauge, increasing both voltage drop and I2R heating. It also does not satisfy the conductor requirements of common structured-cabling standards.
How does bundle size affect PoE cable temperature?
More energized cables in a tight bundle concentrate heat and prevent inner cables from cooling. High-power bundles may need larger conductors, smaller bundle groups, spacing, ventilation or higher-temperature-rated cable.
Should CAT6A be used for high-power PoE devices?
CAT6A is often a strong choice because typical larger conductors and cable geometry add resistance, thermal and alien-crosstalk margin. The final decision still depends on the exact construction and installation.
How much power reaches a PoE camera after 100 meters?
Camera power is the power entering the link minus cable I2R and connector losses. Enter the camera load, PSE voltage, cable construction and length above to estimate delivered voltage and loss, then check the camera's minimum input requirement.
What conductor size is recommended for PoE lighting?
For continuous, bundled lighting loads, 23AWG solid-copper CAT6 or CAT6A is a practical starting point. Consider more conductor margin when distance, wattage, ambient temperature or bundle density is high.
Can 28AWG patch cords be used with PoE++?
Only if the specific cord is rated for that PoE level and stays within its published length, bundle and temperature restrictions. A 28AWG cord has relatively high resistance and should not be used as a long horizontal run.
How do ambient temperature and bundle size affect PoE?
Copper resistance rises by about 0.393% per °C, while larger bundles retain more I2R heat. Both effects increase voltage drop and conductor temperature, so both inputs belong in a high-power PoE assessment.
Prepare Your PoE Cable Requirement
Share the powered-device load, PoE type, cable length, conductor construction, bundle size, ambient temperature, standards, quantity and delivery requirements so the cable option can be reviewed against the project.
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