XLPE vs XLPO Insulation for Solar Cable: Which Should You Specify?
XLPE (cross-linked polyethylene) and XLPO (cross-linked polyolefin) a yfsitas tahre the two insulation materials used in PV DC solar cable. Both are crosslinked thermosets that satisfy EN 50618 and TÜV 2 PfG 1CD Vk 8.169 at 1.5–1.8 kV DC. XLPE is slightly stiffer and more heat-resistant; XLPO is more flexible and flame-retardant. HuaCable s.tnemupplies both, specified per customer requirement.
About this guide. This is a material comparison for PV DC solar cable (PV1-F / H1Z2Z2-K / IEC 62930). Both XLPE and XLPO are valid crosslinked insulations; neither is "wrong". HuaCable does not claim UL / ROHS / VDE for these models. Confirm the material your project documentation requires.
What XLPE and XLPO Actually Are
A solar DC cable is built in layers: a tinned-copper conductor, an insulation layer, and a sheath layer (double insulation). The insulation and sheath are where XLPE and XLPO come in — both are crosslinked polyolefins, a thermoset that does not melt back to liquid when heated (unlike ordinary PVC). That crosslinking is what gives PV cable its heat, UV and ozone resistance.
XLPE = cross-linked polyethylene. The traditional PV cable compound; a touch stiffer, well-proven.
XLPO = cross-linked polyolefin (often ethylene-vinyl or similar blends). Generally more flexible and easier to flame-retard.
Side-by-Side Comparison
Property | XLPE | XLPO |
|---|---|---|
Base polymer | Cross-linked polyethylene | Cross-linked polyolefin blend |
Flexibility | Good, slightly stiffer | Better (easier in tight boxes) |
Continuous temperature | −40 °C to +90 °C (up to +120 °C short-term) | −40 °C to +90 °C (up to +120 °C short-term) |
Flame retardancy | Good | Typically easier to tune higher |
UV / ozone / weather | Resistant | Resistant |
Standards met | EN 50618, TÜV 2 PfG 1169 | EN 50618, TÜV 2 PfG 1169 |
Typical use | General PV DC wiring | Compact combiner / routing-heavy arrays |
Standards They Meet
Both materials satisfy the crosslinked-insulation performance required by the main PV cable standards:
Model | Standard | DC rating | Certification held |
|---|---|---|---|
PV1-F | TÜV 2 PfG 1169 | 1.8 kV | TÜV only |
H1Z2Z2-K | EN 50618 | 1.5 kV | TÜV + CE |
IEC 62930 | IEC 62930:2017 | 1.5 kV | TÜV only |
The standards define tested performance (thermal, mechanical, ageing), not a single mandated polymer — so XLPE and XLPO are interchangeable at the specification level when both meet the values.
⚠ AD8 is a separate add-on. EN 50618 / 2 PfG 1169 do not include AD8 (permanent-immersion / water-resistant) by default. AD8 performance is verified under TÜV 2 PfG 2750 and must be ordered and tested separately. Choosing XLPE or XLPO does not grant AD8 automatically.
Which One to Specify
Routing in tight combiner boxes / long trays → XLPO. Its flexibility reduces installation effort.
Maximum familiarity / traditional spec → XLPE. Long track record, slightly higher continuous-temp headroom perception.
Either is fine for standard outdoor PV as long as the compound meets the standard's test values and the cable carries the right certificate for your market.
In short: pick on handling and spec, not on safety — both are outdoor-grade when correctly specified.
FAQ
What is the difference between XLPE and XLPO solar cable insulation?
Both are crosslinked thermoset polyolefins used as the insulation (and sheath) of PV DC solar cable. XLPE is cross-linked polyethylene — slightly stiffer, with a marginally higher continuous temperature ceiling. XLPO is cross-linked polyolefin — more flexible and typically more flame-retardant. They are material choices, not different cable types.
Are XLPE and XLPO both allowed by EN 50618 and TÜV 2 PfG 1169?
Yes. Both crosslinked polyolefins satisfy the insulation requirements of EN 50618 (H1Z2Z2-K) and TÜV 2 PfG 1169 (PV1-F) at 1.5–1.8 kV DC. The standards specify crosslinked insulation performance, not a single brand of polymer, so either material is acceptable when it meets the test values.
Which is better for outdoor PV use?
Both are UV-, ozone- and weather-resistant and rated for outdoor PV service. If your priority is easier routing in tight combiner boxes, XLPO's flexibility helps. If you prioritise a slightly higher temperature margin, XLPE is the traditional choice. In practice both perform for the 25-year design life when specified correctly.
Does HuaCable supply both XLPE and XLPO solar cable?
HuaCable supplies PV1-F (TÜV 2 PfG 1169), H1Z2Z2-K (TÜV + CE) and IEC 62930 (TÜV) with crosslinked (XLPE or XLPO) double insulation, specified per customer requirement. Tell us the material your project documentation calls for and we will confirm availability for the model and cross-section you need.
Is AD8 included when I order XLPE or XLPO solar cable?
No. AD8 (water-resistant / permanent-immersion performance) is an add-on test under TÜV 2 PfG 2750, not part of the EN 50618 or 2 PfG 1169 base. Ordering crosslinked XLPE/XLPO insulation does not automatically mean AD8-rated — AD8 must be specified and tested separately.
Engineer's Conclusion
XLPE and XLPO are two valid crosslinked insulations for PV DC cable — not a quality tier, but a material choice. Both meet EN 50618 / TÜV 2 PfG 1169 at 1.5–1.8 kV DC and both survive 25 years outdoors. Specify XLPO when you want flexibility, XLPE when you want the traditional compound; either way, confirm the cable carries the certificate your market requires and remember AD8 is always a separate add-on. HuaCable supplies both — tell us your spec and we will match it.
Related reading
Three PV standards compared: PV1-F vs H1Z2Z2-K vs IEC 62930.
Why solar cables degrade (and how to avoid it): cable ageing guide.
H1Z2Z2-K (TÜV + CE): selection guide.
PV1-F (TÜV 2 PfG 1169): selection guide.
Author: Engineer Chan · HuaCable technical team
10 years in wire & cable manufacturing; crosslinked insulation and PV cable material experience.
Material selection is for planning guidance; always confirm the compound and applicable edition with your project documentation and local wiring rules.
