High-Capacity Dimming with Enhanced Thermal Handling

Volt Control System's Dimmer is a continuously variable auto-transformer designed for smooth, stepless AC voltage control. It provides precise voltage regulation for testing, industrial, laboratory, and power control applications. The unit operates on 240V AC input and delivers adjustable output up to 240V AC or 270V AC. For three-phase applications, three units can be connected in star configuration to operate on 415V AC, providing output up to 415V or 470V AC.
Our oil-cooled dimmers provide excellent thermal stability and consistent regulation for heavy-duty industrial processes requiring prolonged operation.

Key Features:

Simple and rugged construction.
Coils made from high-grade CRGO silicon steel and 99.9% pure copper.
Smooth, continuous, breakless, and linear voltage variation proportional to angular rotation.
High operating efficiency with reliable performance
Negligible waveform and power factor distortion.
Excellent short-term overload handling capability
Motorized operation available for remote control applications
Wide range of voltage and current ratings available

Parameter	Manual Type Dimmers / Variac
Models Available	Flush Open Manual (Air Cooled) – F Portable Enclosed Manual (Air Cooled) – P In Tank Manual (Oil Cooled) – T
Operating Voltage	Single Phase: 240V AC, 50–60 Hz Three Phase: 415V AC, 50–60 Hz, 3Φ, 4-Wire
Current Ratings (Air Cooled)	Maximum Current: 0.7A, 2A, 4A, 8A, 10A, 15A, 20A, 28A Continuous Current: 0.6A, 1.8A, 3.8A, 6.5A, 9A, 11.5A, 16A, 22A
Operating Temperature	0°C to 45°C
Insulation Resistance	Minimum 5 MΩ at 500V DC
Dielectric Test	2.5 kV RMS for 1 Minute
Storage Temperature	-9°C to 70°C
Humidity	Up to 95% RH
Conforms To	IS 5142
Cooling Type	Air Cooled / Oil Cooled

Ordering Information

(as per code specified below)

1^st block	Output current rating amps	0.7, 2, 4, 8, 10, 15, 20, 28, 40, 50, 60, 75, 100, 125, 150, 200, 300, 400, 500, 600, 800, 1000, 1200, 1600A
2^nd block	Dimmerstat (D)	Continuously variable voltage auto transformer.
3^rd block	No. of coils	1, 2, 3, 4, 6, 9, 12, 15, 30, 45
4^th block	Type of construction	F, P, T F = Flush, back of panel, open. P = Portable, floor, table mounting, air cooled with enclosure. T = In tank, immersed in oil.
5^th block	Provided with motor drive (M)	"Step-syn" 230V 1Ph AC 50Hz. 60rpm motor having instantaneous start-stop-reverse characteristics.
6^th block	Approx. time in secs. for full rotation sweep time	8, 15, 30, 45, 60, 120 (As per standard gear ratios available)

e.g.

75D3TM15

75 A Dimmerstat with 3 coils (Three phase) in oil-cooled tank construction with motor drive having 15s sweep.

e.g.

8D1P

8A Dimmerstat with 1 coil (single phase). Portable type and suitable for manual operation (no motorisation).

Similarly, other Dimmerstats can be configured and ordered.

Standards Followed
IS5921/1249		Copper cladbase material in electrical/electronic equipment's
IS6297/2026		Transformers and inductors.
IS 6553		Environmental requirements for semiconductors and Integrated circuits.
IS4064		Airbreak switches
IS8828		MCBs
IS 9224		HRC fuses
IS1248		Indicating instruments
IS 6619		Semiconductor Rectifier equipment safety
IS613		Copper busbars
IS2959		Contactors.
IS3231		Electrical relays
IS13703		Low voltage fuses
IS4540		Mono Crystal line Semi conductor rectifier assembly
IS4237		General requirements for switchgear and control switches
IEC62040-2		Electro magnetic conduction and interference.

Mechanical Construction

Single-phase Variable Voltage Dimmers are available in three types:

Portable Type (P): Sheet steel enclosure suitable for floor or table mounting.
Flush Type (F): Open-type construction suitable for panel mounting.
Tank Type (T): Oil-immersed design housed in a sheet steel tank with roller mounting.

Three-phase units are generally supplied as three coils and are available in all three configurations: P, F, and T.

For higher current ratings (above 200 Amps), the units utilize 2/3 or more coils connected in parallel to achieve the required current-carrying capacity.

Motorized models use a 240V AC Step-Synchronous Motor operating at 60 RPM (50Hz). With appropriate gearing, higher torque and lower operating speeds can be achieved.

Standard sweep time options: 8, 15, 30, 45, 60, and 120 seconds.

Our Applications

Auditoriums, Hotels, and Conference Halls
Exhibitions and Laboratories
AC Voltage Stabilizers and Rectifiers
Battery Chargers
Temperature Control of Ovens and Furnaces
Testing of Instruments, Relays, and Circuit Breakers
Welding, Electroplating, and Anodizing Processes
Colleges and Universities
Industrial Testing and Research Applications

1 PHASE PORTABLE MANUAL (OIL COOLED) - 1 T
Current Rating	40	50	60	75	100	125	150	200	300	400	500	600
L (mm)	590	720	720	836.5	835	835	835	835	1155	1255	1155	1255
W (mm)	610	610	610	670	840	840	865	1065	1190	1290	1190	1290
H (mm)	690	945	945	830	1115	1115	1165	1165	1330	1330	1630	1630
Wt (kg)	80	100	100	122	205	210	230	265	450	480	610	650
Oil (Ltrs.)	55	90	100	120	180	180	195	210	325	350	440	460

3 PHASE MOTORISED (OIL COOLED) - 1TM / 2TM / 3TM
Current Rating	40	50	60	75	100	125	150	200	300	400	500	600
L (mm)	590	720	720	835	835	835	835	835	1155	1255	1155	1255
W (mm)	610	610	610	670	840	840	865	1065	1190	1290	1190	1290
H (mm)	680	935	935	812	1100	1100	1150	1150	1315	1315	1615	1615
Wt (kg)	90	110	110	132	215	220	140	275	460	690	620	660
Oil (Ltrs.)	55	90	100	120	180	180	195	210	325	350	440	460

3 PHASE MANUAL (OIL COOLED) - 3T / 6T
Current Rating	40	50	60	75	100	125	150	200	300	400
L (mm)	720	750	850	835	835	835	1055	1355	1640	1960
W (mm)	610	670	770	840	1040	1140	970	1270	1195	1515
H (mm)	1090	1090	1090	1440	1440	1440	1460	1460	1585	1585
Wt (kg)	150	170	185	345	355	370	490	590	1090	1190
Oil (Ltrs.)	115	125	130	245	270	275	330	385	850	925

3 PHASE MOTORISED (OIL COOLED) - 1TM / 2TM / 3TM
Current Rating	40	50	60	75	100	125	150	200	300	400	500	600
L (mm)	590	720	720	835	835	835	835	835	1155	1255	1155	1255
W (mm)	610	610	610	670	840	840	865	1065	1190	1290	1190	1290
H (mm)	680	935	935	812	1100	1100	1150	1150	1315	1315	1615	1615
Wt (kg)	90	110	110	132	215	220	140	275	460	690	620	660
Oil (Ltrs.)	55	90	100	120	180	180	195	210	325	350	440	460

* Due to VCS Policy of continuous improvement in product quality, some feature and Size of items may change.

Note: We also offer customized solutions tailored to specific customer requirements.

High-Capacity Dimming with Enhanced Thermal Handling