What Is the Difference Between FRP and GI Cable Trays?
Proper selection of the material of cable tray is vital when making an industrial electrical installation. Among other materials that have been given consideration are FRP cable tray and GI cable trays.
Though both types serve similar purposes such as providing guidance for the electrical wires, their corrosion resistance, conductivity, weight, maintainability, installation suitability are quite different.
Therefore, what is the difference between FRP cable tray and GI cable tray?
FRP vs GI Cable Tray: Quick Comparison
| Feature | FRP Cable Tray | GI Cable Tray |
|---|---|---|
| Material | Fiberglass-reinforced polymer | Galvanized steel |
| Corrosion resistance | High | Good, but coating can deteriorate |
| Electrical conductivity | Non-conductive | Conductive |
| Weight | Relatively lightweight | Heavier |
| Rusting | Does not rust like steel | Can rust if galvanizing is damaged/exposed |
| Maintenance | Generally low | Coating and corrosion may require attention |
| Chemical environments | Suitable for many applications | Suitability depends on galvanizing and exposure |
| Installation handling | Easier to handle in many cases | Generally heavier |
| Outdoor use | Application dependent; UV-stabilised grades available | Suitable, but corrosion protection must be maintained |
| Magnetic properties | Non-metallic | Metallic |
| Custom fabrication | Available | Available |
| Typical applications | Chemical, water treatment, corrosive and electrical environments | General industrial and commercial applications |
The final choice should always be based on the project environment, cable load, support span, applicable electrical requirements and required service conditions.
What Is an FRP Cable Tray?
A fiber reinforced polymer (FRP) cable tray is produced from fiberglass reinforced polymer.
FRP cable trays are usually designed for areas that have moisture, chemical, salty or corrosive fumes that can damage the metallic cable support system.
According to design, FRP cable trays are available in either channel type or ladder type.
Plastic Fabricators produce FRP cable trays in various sizes and types such as channel and ladder types.
What Is a GI Cable Tray?
GI cable tray is normally made up of steel material which has a coating of zinc in order to protect the underlying steel against corrosion.
The applications of GI trays include:
- Commercial buildings
- Factories
- Warehouses
- Power plant facilities
- General industrial works
- Utility works
The GI coating offers corrosion resistance, but the effectiveness will depend on the surroundings and the condition of the zinc coating.
The coating must be intact for it to provide the necessary corrosion protection to the underlying steel.
1. FRP vs GI: Corrosion Resistance
This is one of the biggest differences.
FRP Cable Tray
Since FRP is naturally corrosion-resistant, it will never rust like metals such as steel. Thus, FRP is ideal in situations where:
- Chemical vapors
- High moisture
- Water
- Salty air
- Corrosive conditions exist
GI Cable Tray
GI cable trays depend on their zinc coating to offer corrosion resistance.
Galvanization will offer adequate protection in a mild environment. Aggressive chemical attack, increased humidity, or damage to the coating can compromise the effectiveness of the protection offered.
Which should you consider?
In very corrosive conditions, perhaps the more suitable choice would be FRP, depending on the particular chemicals and temperatures involved.
2. Electrical Conductivity
There is a great difference between FRP and GI in terms of their electrical properties.
FRP is non-conductive whereas GI steel is conductive.
This makes FRP a preferred material where electrical non-conductivity is a key consideration.
Since GI is metallic, it can be used in the electrical design of the project to cater for bonding and grounding where applicable.
In this regard, the electrical design will have to include the entire cable tray system.
3. Weight and Handling
FRP trays will most often be lighter than corresponding steel cable trays.
This may facilitate ease of transportation, handling and installation in some applications.
GI cable trays consist of steel material and are thus likely to be heavier and more cumbersome to handle and install, especially when the size of the tray and installation distance is large.
Nevertheless, weight should never be the sole criteria used for selecting cable trays.
4. Maintenance Requirements
Maintenance for FRP trays with respect to corrosion or rusting is generally less than that for steel trays.
GI trays, on the other hand, will always need the continuous good condition of their galvanized surface. Any damage during fabrication, transportation or installation could expose the steel surface.
In cases where corrosion plays a big role, this factor must be taken into consideration.
5. Strength and Load Capacity
FRP is lightweight, but that does not mean every FRP tray has the same load capacity as every GI tray or vice versa.
Load capacity depends on:
- Tray profile
- Material thickness
- Tray width
- Tray depth
- Support span
- Cable weight
- Installation arrangement
- Temperature
- Manufacturer’s design
Therefore, comparing only “FRP vs GI” is not enough.
For a proper technical comparison, compare the specific tray models and their tested/rated load capacities at the intended support spacing.
6. Performance in Chemical Industries
Chemical plants can expose cable trays to corrosive vapours, splashes, moisture and aggressive atmospheric conditions.
This is where FRP cable trays can be particularly useful because of their corrosion-resistant construction.
Typical applications can include:
- Chemical processing plants
- Electroplating facilities
- Water-treatment plants
- Wastewater facilities
- Fertilizer plants
- Coastal installations
- Industrial ventilation areas
GI trays can also be used in industrial plants, but the suitability of the galvanized coating must be evaluated against the environment.
7. FRP vs GI Cable Tray for Outdoor Applications
Both are suitable for exterior use; however, the environment is critical.
The manufacturer will need to determine the UV resistance of the FRP material for the given environment.
When using GI, the coating and its resistance to the environment needs to be considered, particularly in an aggressive environment such as a coastal environment.
Outdoor application needs to consider:
temperature + UV + moisture + chemical exposure + support
8. Installation and Fabrication
Both FRP and GI trays can be cut and fabricated to suit project requirements.
However, the installation methods differ because the materials behave differently.
FRP fabrication may involve:
- Cutting
- Drilling
- Notching
- Custom sizing
GI systems commonly involve:
- Cutting
- Drilling
- Bending
- Fabricated fittings
- Bolted connections
When cutting or modifying either material, the finished edges and protective properties should be taken into account.
Plastic Fabricators offers custom cutting, drilling, notching and fabrication options for its FRP cable tray systems.
FRP Cable Tray vs GI Cable Tray: Which One Should You Choose?
There is no universal answer.
Choose FRP when your project places high importance on:
- Corrosion resistance
- Non-conductivity
- Lightweight construction
- Low corrosion-related maintenance
- Chemical or wet environments
GI may be considered when your project requires:
- A conventional metallic cable-support system
- Established steel-tray specifications
- Conductive metallic construction
- General industrial or commercial cable routing
The final choice should be based on environment, structural loading, electrical design requirements, project standards and total lifecycle considerations.
FRP vs GI Cable Tray: Cost Consideration
This is just one component of the decision.
A true comparison must take into account:
Purchase cost + Support cost + Installation cost + Maintenance cost + Corrosion prevention + Replacements
GI might be more economical at the stage of procurement cost in some applications, whereas FRP may hold a higher advantage with respect to corrosion.
Thus, do a life cycle cost comparison, not just the quotation.
What Should You Check Before Buying?
The key distinguishing factor between FRP and GI cable trays is the actual composition of the two materials: one being fiberglass reinforced polymer and the other galvanized steel.
There are many benefits that FRP can bring to the table compared to GI when considering factors like corrosion resistance, light weight and conductivity.
In order to make the right choice of material for any industrial project, these and many more factors need to be considered, among others.
Need FRP cable trays for an industrial plant or any industrial project? Just send us your cable loading schedule and support dimensions, and we will recommend the best fit for you.
Final Takeaway
The calculation of the correct FRP cable tray size depends on the cable schedule you have, not the tray catalog.
Find out the total outer diameter of your cables, the needed space between them, and choose the most suitable standard tray size. Then, check the tray depth, the loading, cable segregation and installation requirements.
To get a personalized FRP cable tray suggestion, provide your cable schedule, cable diameters, routing distance, span and application specifics to the manufacturer.
How to choose the right FRP cable tray size? Send your cable schedule to Plastic Fabricators and we’ll suggest the correct FRP cable tray size and quote the price.