RFOU Cable FAQ: Most Common Questions
The RFOU cable is the standard offshore power cable, and engineers often have questions about its installation, maintenance, and when to use it vs BFOU. This RFOU FAQ addresses the most frequently asked questions from TEBAOFLEX offshore customers.
For complete specifications, see our RFOU product page and specifications guide.
Fire Performance FAQ
Q1: Is RFOU cable fire-resistant?
A: No. RFOU is flame-retardant (IEC 60332-3-22) but not fire-resistant. This means:
- Flame retardant: Cable will not propagate fire — self-extinguishing when flame removed
- Not fire resistant: Cable will NOT maintain circuit integrity during fire — power will be lost
For fire-critical circuits (fire pumps, emergency lighting, ESD), use BFOU cable with IEC 60331 fire resistance rating.
Q2: What’s the difference between flame retardant and fire resistant?
A: These are fundamentally different:
- Flame retardant (IEC 60332): Cable self-extinguishes — does not spread fire. Power is lost during fire.
- Fire resistant (IEC 60331): Cable maintains circuit integrity during fire — power stays on at 750-950°C.
RFOU = flame retardant only. BFOU = both flame retardant and fire resistant. See our RFOU vs BFOU comparison.
Installation FAQ
Q3: What is the minimum bending radius for RFOU?
A: Minimum bending radius:
- Fixed installation: 8 × overall diameter (8D)
- During installation: 10 × overall diameter (10D)
For example, RFOU 3×25mm² with 27mm OD requires minimum 216mm fixed and 270mm during installation.
Q4: What cable glands should I use with RFOU?
A: Use weatherproof brass or stainless steel glands:
- Material: Nickel-plated brass or 316 stainless steel
- IP rating: Minimum IP66 outdoor, IP67 for splash zones
- Armour termination: Glands with armour clamp for steel wire braid
- Approvals: DNV or ATEX certified for offshore
Q5: Can RFOU be installed outdoors on deck?
A: Yes. RFOU is designed for outdoor offshore exposure:
- LSZH sheath is UV stabilized
- Temperature range: -20°C to +60°C ambient
- Oil and chemical resistant for deck exposure
- Steel wire braid provides mechanical protection
- Orange ST1 sheath provides visual identification
Q6: How should RFOU be routed through bulkheads?
A: Use fire-rated MCT (multi-cable transit) systems:
- Steel MCT frames welded to bulkhead
- Fire-rated rubber blocks sized to cable OD
- MCT fire rating must match bulkhead rating (A-60, H-60, H-120)
- Proper compression ensures fire and water tightness
Maintenance and Troubleshooting FAQ
Q7: How often should I test RFOU cable insulation?
A: Recommended testing:
- New installation: 1kV Megger before energizing
- Annual visual: Check sheath, glands, MCT transits, cable tray supports
- Annual insulation test: 1kV between cores and to ground
- After any fault: Test before re-energizing
Minimum acceptable: >100 MΩ new, >10 MΩ in-service. See our cable maintenance guide.
Q8: What are common causes of RFOU cable failure?
A: Common failure modes:
- Sheath damage: Mechanical damage from deck operations, dropped objects
- UV degradation: Long-term deck exposure causing sheath cracking (rare with LSZH)
- Armour corrosion: Steel wire braid corrosion through sheath damage
- Water ingress: Through improperly sealed glands or damaged MCT blocks
- Vibration fatigue: Conductor strand breakage at rigid terminations
- Cable tray abrasion: Friction at tray edges and support points
Q9: Can RFOU cable be repaired?
A: Yes, but use proper procedures:
- Minor sheath damage: Self-amalgamating tape + PVC overwrap (temporary)
- Sheath + armour damage: Cable repair kit with armour restoration
- Conductor damage: Inline compression joint with insulation and armour restoration
- Severe damage: Replace cable section — do not attempt multiple field repairs
All repairs must be insulation tested before re-energizing.
Q10: What is the service life of RFOU cable?
A: Expected service life:
- Normal offshore service: 20-25+ years
- Deck exposure: 15-20 years (UV, salt spray)
- Engine room: 15-20 years depending on temperature
Q11: How do I identify genuine RFOU cable?
A: Check for:
- Cable marking: “RFOU” with 0.6/1kV, NEK 606, manufacturer name
- Sheath color: Orange (ST1 LSZH) standard
- Construction: Tinned copper, EPR insulation, steel wire braid, LSZH sheath
- No fire barrier: Unlike BFOU, RFOU has no mica glass tape
- Certifications: DNV, ABS, LR, or BV type approval
Still Have Questions?
TEBAOFLEX technical support is available for:
- RFOU cable sizing and selection for offshore power distribution
- Classification society compliance
- Installation planning including MCT transit sizing
- Determining when to upgrade from RFOU to BFOU
- Quotation and delivery timeline
Contact TEBAOFLEX engineering for expert assistance and competitive pricing on RFOU offshore power cables.
