Resources
Frequently Asked Questions
Answers to common questions about product availability, sizing, quotations, circuit protection, project supply, installation and commissioning.
Supply & Stock
Yes. We hold selected common ratings across our core product ranges in Singapore for faster project fulfilment. This includes selected VSDs, soft starters, circuit protection and control products.
For specific models or ratings that are not held readily, we can advise the expected lead time before you place an order. Send us the motor rating, voltage, application, quantity or board schedule, and we’ll check availability.
We can support more than the drive alone.
Depending on your requirement, Trans-Digi can supply VSDs or soft starters together with MCCBs, MCBs, RCCBs, contactors, overload relays and related control devices for the panel.
This allows the main motor-control and protection components to be selected together rather than treated as separate requirements.
For straightforward requirements, we aim to respond within the same business day.
To help us quote quickly, send the motor rating, supply voltage, application, quantity and required product type. For panel requirements, you can also send us the board schedule or single-line diagram.
WhatsApp is usually the fastest way to reach our sales and technical team.
Lead times depend on the product model, rating, quantity and manufacturer availability.
Where an item is not available from local stock, we will advise the expected lead time before order confirmation. If timing is critical, we can also review whether a suitable alternative within our product range is available.
Yes. Trans-Digi has supplied and supported various public-sector, institutional and infrastructure projects in Singapore.
We can also provide relevant technical datasheets, product documentation and supporting submission materials for project requirements where available.
Selection & Sizing
Use a soft starter when the motor operates at a fixed speed and you mainly need controlled starting and stopping.
Choose a variable speed drive (VSD) when the application requires speed control during operation, such as pumps, fans and other variable-demand loads. VSDs can also support functions such as PID control, sequencing and communication with building or plant control systems.
To size a VSD correctly, we typically need the motor power (kW), full-load current, supply voltage, phase and application.
It is also helpful to know the operating duty, load characteristics and installation environment. A clear photo of the motor nameplate will usually provide most of the basic electrical information required for initial selection.
It depends on the electrical installation and application.
A line reactor may be considered where supply conditions, harmonics or multiple drives on the same electrical system need to be addressed. A load reactor may be required where the cable distance between the VSD and motor is long or additional motor-side protection is needed.
Send us the drive rating, motor details and approximate cable length, and we can advise on the appropriate accessory requirements.
Yes. Communication options such as Modbus RTU, Modbus TCP and BACnet are available across selected VSD ranges.
The exact protocol may be built into the drive or require an optional communication module. Let us know the BMS protocol and control requirements, and we can recommend a suitable VSD and communication option.
A board schedule or single-line diagram is the best starting point.
Where these are not available, send us the incoming supply details, number of outgoing circuits, required ratings and the loads each circuit serves. We can then review the required MCBs, MCCBs, RCCBs or RCBOs and other associated protection and switching devices for the quotation.
Circuit Protection & Switchgear
The correct RCD type depends on the drive, supply arrangement and the type of residual current the VSD can produce.
In general, standard Type AC devices may not be suitable for VSD applications. Depending on the drive and installation, Type A, Type F or Type B protection may be required. For three-phase VSD applications, Type B is commonly considered where smooth DC residual current may be present.
Always check the VSD manufacturer’s requirements and the project protection design before selecting the RCD.
An RCCB provides residual-current protection but does not provide overload or short-circuit protection, so it must be used together with an upstream MCB or MCCB.
An RCBO combines residual-current, overload and short-circuit protection in a single device and typically protects an individual outgoing circuit.
The choice depends on the board design, required circuit segregation, available space and how much of the installation should remain operational if one circuit develops an earth fault.
The correct MCB curve depends mainly on the load’s expected inrush current.
B-curve breakers are generally used for loads with relatively low inrush current, such as lighting and general resistive circuits.
C-curve breakers tolerate higher starting current and are commonly used for general distribution and smaller motor loads.
D-curve breakers allow significantly higher inrush and may be suitable for transformers, larger motors and other high-starting-current equipment.
The final selection should consider both the connected load and the required fault-protection characteristics of the circuit.
Breaking capacity should be selected according to the prospective short-circuit current at the installation point.
A 6 kA breaker may be suitable where the available fault current is lower, while installations closer to transformers or larger electrical supplies may require 10 kA or higher.
The required rating should be confirmed from the project’s electrical design or short-circuit calculation rather than selected purely as a preference.
A contactor should be selected according to the motor rating, operating current, supply voltage and utilisation category.
For standard squirrel-cage motors that start and stop under normal running conditions, AC-3 is the commonly used utilisation category. Other applications, such as inching, plugging or frequent reversing, may require a different category and larger contactor.
Send us the motor kW, full-load current, voltage and starter arrangement, and we can help select the contactor together with the appropriate overload relay.
Installation, Commissioning & Support
We support both product supply and complete project execution.
Depending on the project scope, Trans-Digi can provide equipment supply, mechanical installation, power and control wiring, parameter configuration, functional testing and live commissioning. Clients can engage us for the full scope or only the individual services they require.
Yes. Where included in the project scope, we provide as-built documentation, final parameter settings and relevant product documentation as part of project handover.
Technical datasheets, manuals and supporting product documents are also available for the products we supply.
Products supplied by Trans-Digi are covered by the applicable manufacturer warranty, subject to the specific product range and warranty terms.
Warranty periods and conditions can vary by manufacturer and model, so the applicable warranty will be confirmed as part of the quotation or product documentation.
Our support continues after commissioning and project handover.
We can assist with fault diagnosis, parameter adjustments, operating questions, replacement requirements and troubleshooting for installed equipment. For urgent technical enquiries, WhatsApp provides a direct route to our sales and technical support team.
Where possible, we aim to respond within the same business day during business hours.
The fastest way to reach us is by WhatsApp or phone at +65 8028 4462.
For quotations and technical enquiries, send us the product requirement, motor rating, application, nameplate photo, board schedule or any available project information.
For formal RFQs, specifications or documentation requests, email enquiry@transdg.com.
Business hours: Monday to Friday, 8.30am–5.30pm (SGT).
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