Products / DCC-III
Rack mount Static transfer switch
DCC-III
The DCC-II platform in a 4-pole, three-phase build. The fourth pole transfers the neutral for 208/120 V racks up to 18 kW.
Made in the USA with U.S. and imported parts
Current rating50 A
1 standard rating. 100% continuous duty.
Voltage208/120 V
Three phase, 50 Hz or 60 Hz.
Switched poles4
4-pole builds transfer the neutral too.
Transfer time¼ cycle
As fast as, per phase: 4.2 ms at 60 Hz, 5 ms at 50 Hz. SCR-based, break-before-make.
Ratings
| Type | Static transfer switch (STS) |
|---|---|
| Mounting | Rack mount |
| Phase and poles | Three-phase 4-pole |
| Voltages | 208/120 V |
| Current ratings | 50 A |
| Frequency | 50 Hz or 60 Hz |
What it does
- Four poles: the neutral is disconnected and reconnected with the phases
- SCR-based static transfer as fast as ¼ cycle per phase
- Hot-swappable electronic module in a 4U chassis: MTTR under 2 minutes, with a built-in bypass isolation switch (7-position selector)
- 208/120 V, 50 A, 18 kW
- Remote alarm contacts and Modbus RTU via RS-485
- Power Quality Seeking, redundant logic supplies and fans, self-diagnostics, and a 22 kA short-circuit rating
- TÜV certified to UL 1008 and CSA; CE marked
Reading the model number
Format D3-FVVVAA-C-I, for example D3-620850-RC-TB
D3Base model
FFrequency: 6 = 60 Hz, 5 = 50 Hz
VVVVoltage, e.g. 208
AACurrent, e.g. 50 = 50 A
CComms: RC remote contacts and Modbus RTU via RS-485
II/O: TB terminal block
Specifications
Transfer
| Sense and transfer time | As fast as ¼ cycle per phase (4.2 ms @ 60 Hz, 5 ms @ 50 Hz) |
|---|---|
| Reliability | MTBF > 1 million hours; MTTR < 2 minutes |
Bypass
| Maintenance bypass | Internal maintenance bypass isolation switch, 7-position selector; hot-swappable electronic module; mechanical interlocks optional (Interlock I and II) |
|---|
Controls and monitoring
| Panel indicators | Source available, preferred, on-source; alarms: not on preferred, MBS off normal, no sync, OL/OT, service EM, do not bypass |
|---|---|
| Panel controls | Preferred select, alarm silence, lamp test, bypass isolation selector, diagnostics (self test) |
| Remote contacts | 2: summary alarm, service EM |
| Communications | Modbus RTU via RS-485 (standard) |
| User settings | Over/under voltage, phase angle for manual transfer, default preferred, do not bypass, unit address, auto-retransfer on/off |
| Protection logic | Anti-cross-connection logic; Power Quality Seeking; shorted/open SCR protection; self-diagnostic scanning; redundant logic supplies; redundant fans; built-in voltage suppression and transient (surge) protection |
Connections
| Input and output | Terminal blocks |
|---|
Protection
| Short-circuit rating | 22 kA |
|---|
Mechanical
| Dimensions H × W × D | 7 × 19 × 33 in (178 × 483 × 838 mm) |
|---|---|
| Weight | 65 lb (29.5 kg) |
| Cooling | Redundant fans |
Environment
| Operating temperature | 32–104 °F (0–40 °C) |
|---|---|
| Humidity | 0–95% non-condensing |
Compliance
| Certifications | TÜV certified to UL 1008 and CSA; CE marked |
|---|---|
| Standard warranty | 12 months from start-up or 18 months from shipment, whichever is sooner |
Installation
| Rack mounting | Use a rack shelf and cable strain relief where the unit weight exceeds the two-post mounting capacity of the rack. |
|---|
Specifications are subject to change without notice. Wire sizes and installation details: ask our engineers.
