Conversions Tech Soar
Frequently Asked Questions
Conversions Tech inc Solar Cables & Balance-of-System Components
Conversions Tech inc manufactures UL 4703 1500 V DC PV wire, pre-terminated MC4-Evo2 jumpers, harnesses, string fusing, combiner boxes, and rapid-shutdown devices. Below are 40 questions—ranging from homeowner basics to utility-scale engineering—to help you design, install, and maintain resilient photovoltaic systems.
1. What is PV wire, and how is it different from USE-2?
PV wire carries dual-layer insulation—XLPE over cross-linked polyolefin—rated 1500 V DC, 90 °C wet, UV-resistant, and sunlight-resistant per UL 4703. USE-2 is single-insulated, 600 V, and cannot serve ungrounded arrays per NEC 690.35.
2. What conductor sizes do Conversions Tech inc PV wires cover?
Stock sizes run from 18 AWG stranded sensor leads to 500 kcmil aluminum for central-inverter homeruns; most field strings use 10 AWG (6 mm²).
3. Are your MC4 connectors UL 6703 certified?
Yes—male and female terminations carry UL 6703 and TÜV EN 62852 marks, 1500 V DC, 30 A (2.5–4 mm²) / 50 A (6 mm²) continuous.
4. What jacket temperature range do PV wires support?
−40 °C cold bend to +125 °C dry; ampacity tables assume 90 °C conductor.
5. Can PV wire be direct-buried?
Yes—our PV wire is dual-rated RHW-2 / XHHW-2 for direct burial without conduit when permitted by local AHJ.
6. What is NEC 690.12 rapid-shutdown, and do your string cables support it?
Rapid-shutdown requires array voltage at conductors ≥ 1 ft from the array to drop below 30 V within 30 s of AC loss. Our pre-wired module-level power electronics (MLPE) harnesses integrate signal leads for RSD compliance.
7. Do your combiner boxes include surge protection?
Yes—Type 1 / 2 MOV SPD cartridges rated 1500 V DC, Imax = 40 kA; replaceable via slide-in cassettes.
8. What fuse rating should I use for 12-string combiner wires?
NEC 690.9(B) requires ISC×1.25×1.25. For 13 A short-circuit, choose a 20 A 1500 V DC gPV fuse.
9. What is Potential Induced Degradation (PID), and are your cables PID-free?
PID occurs when leakage currents between cells and grounded frames cause power loss. Our XLPE insulation has ≤ 1012 Ω · cm volume resistivity, mitigating PID paths.
10. Do you supply ground-bond jumpers for microinverters?
Yes—6 AWG bare copper with stainless serrated-washer lugs, pre-cut 10–48 in lengths, UL 467 listed.
11. How do I calculate open-circuit string voltage at −10 °C?
Voc-temp = Voc-STC + (βvoc × ΔT). With β ≈ −0.28 %/°C, 38 V oc module: ΔT = 25 °−(−10 °)=35 °. Voc ≈ 38 V + (−0.0028×35×38) ≈ 41.7 V. Multiply by modules per string.
12. What is the maximum cable capacitance for string inverters with AFCI?
Most inverter AFCI circuits tolerate ≤ 4 µF to ground. Our low-capacitance XLPE PV wire measures 30 pF/m; 100 m homerun = 3 nF—well below limit.
13. Can I run PV wire in EMT conduit with AC circuits?
No—the NEC prohibits DC and AC conductors > 30 V in the same raceway unless all insulation is rated for the highest voltage present and conductors originate in the same equipment. Keep PV homeruns separate.
14. What crimp tool do you recommend for MC4 pins?
We supply a ratcheting 2-impression hex die (2.5/4/6 mm²). UL 6703 listing requires pull test ≥ 310 N on 4 mm² conductors.
15. Are your battery cables UL 1977 for ESS?
Yes—fine-strand flex cable with EPDM jacket, 1000 V DC, FT1 flame, tested to UL 1977 for field-wired energy-storage connectors.
16. Do you stock aluminum PV cable for utility trackers?
Yes—2/0–500 kcmil AA-8176-Strand compact with UV-black XLPE, 35 % lighter, 60 % cost of copper.
17. What’s the bend radius for 4/0 AWG PV cable?
Minimum = 5× OD; 4/0 OD ~ 17 mm ⇒ 85 mm (3.4 in).
18. How is string polarity marked?
Positive conductors: red heat-shrink every 2 m; negative: black. White used only for grounded conductors on legacy 600 V arrays.
19. What is the corona inception voltage (CIV) of 1500 V PV wire at 15 kHz PWM?
Partial-discharge test per IEC 62852 shows CIV ≈ 4 kVpk on 10 AWG—well above 1.5 kV system transients.
20. Are your XLPE jackets compatible with bifacial tracker torque-tube clips?
Yes—abrasion testing ASTM D1044 Taber 500 cycles Δm < 5 mg; no jacket chalking against stainless clips.
21. Do PV wires suffer from rodent damage?
Our “Rodent-Guard” option adds a nylon-12 outer jacket containing capsaicin deterrent; chew-test shows 95 % reduction in gnaw marks versus standard XLPE.
22. What is the flame rating of PV cable bundles in rooftop arrays?
Our PV-FR cable passes UL 1685 FT4 (1.5 m char ≤ 610 mm), meeting 2023 NFPA 855 rooftop ESS ventilation criteria.
23. How do you mitigate voltage rise on 100-ft 10 AWG homeruns?
10 AWG Cu RDC=1 mΩ/ft; I=10 A → Vdrop=1 mV/ft ×100=0.1 V (0.07 %). Well under NEC 310.16 3 % recommendation.
24. What contact resistance spec applies to MC4 mates after 25 years?
≤ 0.35 mΩ post-aging (85 °C/85 % RH, 1000 h) per IEC 62852 Annex D. Ours avg 0.22 mΩ.
25. Are cables resistant to ammonia from dairy-roof installs?
Yes—tested ISO 4892 ammonia chamber 1000 ppm × 21 days; no jacket cracking or tensile loss.
26. What is the maximum array current for 6 mm² (10 AWG) PV wire in 50 °C ambient?
Table 310.16: 55 A (90 °C column). Apply 1.04 temp adder for 50 °C → Iadj = 53 A.
27. How is cable ageing tested for UV-C disinfectant exposure on carports?
750 W m⁻² UV-C 254 nm lamp 168 h; ΔE color shift < 1.5, elongation retention > 80 %.
28. Do combiner boxes support Modbus TCP monitoring?
Yes—DIN-rail gateway converts RS-485 string meter data to Ethernet Modbus TCP/IP for SCADA.
29. What’s the fault-current withstand of PV wire under inverter back-feed?
10 AWG copper survives 5 kA DC for 0.1 s without jacket breach per UL 9703.
30. Does XLPE outgas silicone, affecting bifacial soiling?
No—FTIR shows no volatile siloxanes; chamber test < 1 ppm organosilicone after 100 °C bake.
31. Are aluminum conductors allowed in rooftop PV under NEC?
Yes for exposed runs ≥ 4 AWG with dual-rated AL9CU terminals; derate 1 AWG size versus copper to match ampacity.
32. Do your PV wires meet EN 50618 (Europe) as well?
Yes—H1Z2Z2-K dual mark, TÜV certificate R 60135100, 18/30 kV impulse withstand.
33. How do you guarantee hydrogen-sulfide resistance on geothermal sites?
Immersion test 500 ppm H₂S @ 70 °C; no embrittlement or jacket blistering observed.
34. What is the trans-impedance of MC4 connectors at 1 MHz?
Zdiff ≈ 4 mΩ; insertion loss −0.02 dB—negligible in DC systems, but relevant to PLC rapid-shutdown carriers.
35. Can PV wire share the same cable tray with CAT6 Ethernet?
Allowed if a solid fixed barrier separates power from communication per NEC 300.5(D)(3); otherwise maintain 2 in spacing.
36. Do your RSD harnesses support SunSpec signal power line?
Yes—two extra 18 AWG twisted-pair leads rated 20 kHz PWM 30 V for SunSpec-cert rapid-shutdown signal.
37. What is the dielectric withstand test you perform on 1500 V cables?
6 kV DC for 1 min, leakage ≤ 5 mA, per UL 4703 Section 8.
38. Will PV wires support floating or bipolar 1500 V arrays?
Yes—insulation tested 1.2× Umax = 1800 V DC; corona discharge remains below 5 pC at 15 kHz switching.
39. Do you offer pre-terminated homeruns with ring-tongue lugs?
Yes—crimped and heat-shrink sealed, compression-lug pull-out exceeds UL 486A/B by 20 %.
40. What warranty covers Conversions Tech inc solar cables?
25-year limited warranty for jacket cracking, insulation breakdown, and connector contact resistance when installed per NEC and our torque chart.
