Description
📋 Product Overview
The DEIF FAS-113DG is a Uni-line automatic synchroniser designed to synchronize a generator with a busbar before closing the generator circuit breaker. It continuously compares generator and busbar voltage, frequency, and phase angle, then issues the breaker-closing signal when the programmed synchronization conditions are satisfied.
The unit also compensates for the circuit breaker’s closing time. Instead of simply waiting until the phase angle reaches zero, the FAS-113DG calculates the required phase-angle advance using the actual slip frequency and the configured breaker closing time. This is important in generator applications where the breaker needs a finite mechanical closing time.
For the configuration represented by the supplied product description, the unit is specified for 440V AC measurement and 24V DC auxiliary supply, with Option A / 60 Hz configurations available in the FAS-113DG ordering system. Always compare the product label with the generator switchboard drawings before installation because FAS-113DG units were manufactured in several voltage and option combinations.
⚙️ Key Features
- Automatic generator-to-busbar synchronization
- Circuit breaker closing-time compensation
- Generator frequency control through speed-control relay outputs
- Voltage and frequency difference monitoring
- Synchronizing relay output
- LED indication for generator voltage, busbar voltage, frequency difference, voltage difference and synchronization status
- Adjustable slip-frequency setting
- Adjustable acceptable voltage difference
- Adjustable breaker closing time
- Built-in self-monitoring function
- 35 mm DIN-rail or base mounting
- Suitable for applications ranging from diesel generators to gas turbines
- Uni-line architecture for generator protection and control applications
📊 Product Datasheet
| Parameter | Specification |
|---|---|
| Brand | DEIF |
| Model | FAS-113DG |
| Product type | Automatic generator synchroniser |
| Application | Generator-to-busbar synchronization |
| Synchronization variables | Voltage, frequency and phase angle |
| Measurement voltage range | 57.7–690 V AC depending on configured variant |
| Supplied configuration | 440 V AC measurement / 24 V DC supply, subject to exact variant |
| Frequency range | 40–45–65–70 Hz |
| Breaker closing pulse | 400 ms ±10 ms |
| Slip-frequency setting | 0.05–0.5 Hz |
| Voltage difference setting | ±2–±12% of busbar voltage |
| Breaker closing-time setting | 20–200 ms |
| Extended breaker setting | 200–400 ms with Option E |
| Control pulse length | 25–500 ms |
| Operating temperature | -25 to +70°C |
| Case protection | IP40 |
| Terminal protection | IP20 |
| Mounting | 35 mm DIN rail or base mounting |
| Approx. weight | 0.75 kg |
| Product family | DEIF Uni-line |
The measurement-voltage range is broad because FAS-113DG was supplied in different configured versions; the exact unit must therefore be matched to its nameplate and ordering information rather than assuming every FAS-113DG accepts the same nominal voltage.
🔌 Operating Function
During synchronization, the FAS-113DG measures the generator and busbar voltages through its dedicated measurement inputs. It checks the voltage difference, frequency difference and phase relationship.
When the programmed conditions are met, the synchroniser calculates the required phase-angle advance according to the generator’s slip frequency and circuit breaker closing time. It then energizes the synchronization relay and sends the breaker-closing command.
The standard breaker relay provides a closing pulse of approximately 400 ms. The unit also provides relay contacts for increasing and decreasing generator speed, allowing the governor or speed-control circuit to bring the generator frequency toward the required synchronization point.
The front LEDs provide useful commissioning information, including generator voltage, busbar voltage, frequency difference, voltage difference and synchronization status.
🔧 Installation & Configuration
Before installation, confirm three items from the actual unit:
- Measurement voltage
- Auxiliary supply voltage
- Frequency and option configuration
This is particularly important for a 440V system. DEIF lists several FAS-113DG measurement and supply variants, so the terminal wiring should follow the exact product variant rather than a generic FAS-113DG diagram.
The unit can be installed on a 35 mm DIN rail or mounted directly on a suitable base. The installation instructions identify separate inputs for busbar voltage and generator voltage, together with the breaker relay and speed-control contacts.
Typical commissioning adjustments include:
- fSET: slip-frequency setting
- ΔUmax: allowable voltage difference
- TBC: circuit breaker closing time
- TN: minimum control pulse duration
- XP: proportional control band
The installation documentation recommends setting the breaker closing-time value according to the actual circuit breaker. An incorrect breaker-time setting can directly affect synchronization accuracy.
🏭 Application Scenarios & Practical Pain Points
Standby Generator Systems
The FAS-113DG can be used where a standby generator must be synchronized with an energized busbar before closing its breaker.
Industrial Generator Plants
In industrial power systems, the synchroniser can coordinate generator frequency with the existing busbar before connection, reducing the risk associated with an incorrect breaker-closing condition.
Diesel Generator Sets
The control pulses can be configured for slower-reacting prime movers such as diesel engines.
Gas Turbine Generator Systems
The same synchroniser can be applied to faster-reacting prime movers, including gas turbines, provided the control-loop characteristics and settings are correctly configured.
Common Commissioning Problems
Breaker closes too early or too late:
Check the TBC breaker closing-time setting against the actual breaker specification.
Generator frequency does not approach the busbar frequency correctly:
Check the speed-control relay wiring, governor response and XP/frequency settings.
Synchronization does not occur:
Check generator voltage, busbar voltage, frequency difference, voltage difference and phase sequence.
Unstable synchronization:
Investigate governor response, voltage-signal quality, harmonic distortion and the configured slip-frequency setting. The FAS-113DG incorporates filtering and a df/dt-related protection function to help prevent an incorrect synchronization pulse under unstable signal conditions.
🧰 Maintenance Recommendations
The FAS-113DG is an electronic synchronising relay, so preventive maintenance should concentrate on wiring, settings and signal quality rather than mechanical servicing.
- Inspect terminal connections periodically.
- Verify that the 440V measurement inputs correspond to the installed configuration.
- Check the 24V DC auxiliary supply under operating conditions.
- Confirm the breaker closing-time setting after breaker maintenance or replacement.
- Check the speed-increase and speed-decrease relay circuits.
- Monitor the front-panel LEDs during commissioning and troubleshooting.
- Keep the enclosure clean and dry.
- Avoid unauthorized adjustment of synchronization parameters.
- For DC pilot motors, use an external auxiliary relay and suitable transient suppression as recommended in the installation instructions.
The front cover can also be sealed after commissioning to help prevent unwanted changes to the settings.
❓ FAQ
Q1: What is the DEIF FAS-113DG used for?
It is an automatic synchroniser for connecting a generator to a busbar and controlling the circuit-breaker closing process.
Q2: Can it be used with a 440V generator system?
Yes. 440V AC is one of the listed FAS-113DG measurement-voltage configurations. The exact variant and auxiliary supply must still be confirmed from the nameplate.
Q3: Is the 24V DC supply the same as the measured generator voltage?
No. The auxiliary supply and AC measurement voltage are separate specifications. A 440V AC / 24V DC configuration means the unit measures the AC system while being powered from a 24V DC control supply.
Q4: Does the FAS-113DG directly control the generator speed?
It provides relay outputs for increasing and decreasing speed. These outputs are intended to interface with the generator’s speed-control system rather than replace the governor itself.
Q5: What happens if the circuit breaker closing time is configured incorrectly?
The phase-angle advance calculation will be incorrect, which can affect the timing of the breaker-closing command. The actual breaker closing time should therefore be used during commissioning.
Q6: What should be checked before replacing an existing FAS-113DG?
Check the complete part configuration: measurement voltage, auxiliary supply, generator frequency and installed options. Two FAS-113DG units may have the same base model but different configured electrical characteristics.
🔄 Related DEIF Models
For replacement planning or system upgrades, the following DEIF models may be relevant:
- FAS-113DG – Automatic synchroniser
- FAS-115DG – Automatic synchroniser with related synchronization functions
- HAS-111DG – Semi-automatic/manual synchronising relay
- CSQ-3 – Check synchronising relay
- LSU-112DG – Load sharing unit
- LSU-113DG – Load sharing unit
- LSU-114DG – Load sharing unit
- LSU-122DG – Load sharing / voltage control unit
- PPU – DEIF power management platform
- GPC – Generator controller family
DEIF identifies FAS-113DG and FAS-115DG as automatic synchronising products, while HAS-111DG provides semi-automatic/manual synchronization functionality.
📌 Application Summary
The DEIF FAS-113DG is best understood as a dedicated generator synchronising and circuit-breaker closing controller, rather than a general-purpose PLC or protection relay.
Its main job is straightforward but important: compare the generator and busbar electrical conditions, regulate generator frequency through its control outputs, compensate for breaker closing time, and issue the synchronization command only when the configured conditions are satisfied.
For a 440V AC / 24V DC installation, the most important purchasing and replacement check is the exact variant shown on the unit label. DEIF’s documentation confirms multiple measurement-voltage, supply-voltage and option combinations, so matching the part configuration is essential before installation.
For technical reference, DEIF’s FAS-113DG product documentation provides the manufacturer specifications and application information.
