For applications requiring excitation current 15 Amps to 10,000 Amps

ECS2100 — DECS-400 — DECS-300 —
Alterrex Convection-Cooled Bridges — DECS-200/200N Pan Chassis — PSS-100 —
Rotating Diode Modules — Synchronous Motor Control

 

Basler Offers New High Power Convection-Cooled Bridges for
GE Alterrex Systems

Water-cooled excitation systems were developed in the early 1970s to provide DC to the generator field for the large GE Alterrex generator systems. The system consisted of an AC rotating exciter providing a three phase output connected to multiple remote stationary diode rectifier bridges.

Larger generators requiring higher field amperages often had three or more water-cooled bridges connected in parallel with N+ 1 redundancy in the event of bridge failure. To isolate a defective bridge and allow maintenance, each bridge included a five-pole manual disconnect switch to isolate the AC input and DC output.

Today, 30-40 years later, the water-cooled mechanism to cool the power semiconductors have deteriorated to the point where water leaks are prevalent in the Alterrex system. Elbow and tube leaks are typical issues, along with Teflon carbonizing that leads to eventual isolation of the rectifier bridge, requiring repair. For some plants, two or more leaks may be common in a year’s time.

Existing technology leaves you:

• Tired of water leaks and plumbing repairs
• Coping with nuisance field grounds due to water leaks
• Dealing with obsolete parts
• Fearing long lead times/ down times
   

Drop in Replacement Solution Offering Convenience and Reliability
 

The solution is new technology. High-performance heat sink extrusions for maximum heat efficiency are combined with high ampere semiconductors that are arranged in a three phase full wave configuration utilizing convection-cooled semiconductors in lieu of the water-cooled semiconductors of the past. Convection-cooled bridges eliminate the maintenance and headaches associated with deionizing water, corroded plumbing and even fans.

The new Basler convection-cooled bridge is specifically designed to be located in the same mounting location as the existing water-cooled rectifier bridges. Basler Electric offers several combinations for consideration. In each case, it is intended that the original water cooled rectifier bridge would be replaced with Basler Electric's convection cooled rectifier bridge.

The options consist of:

Save Money and Time

The Basler “Drop-in Replacement” solution eliminates the need to make a prohibitive expenditure for a complete static exciter changeout and offers a fast 8 week product delivery to meet emergency needs.

Other options include a replacement door mounted interface panel housing DC meters, temperature indicators, and pilot light, if required.

For more information, see Application Note EX-ALT_BRDG - Convection-cooled DECS-400 retrofit solutions for the water-cooled Alterrex main field stationary bridges and

Special Features as Standard

• 6 RTDS per bridge for monitoring
• 3 in line power interrupt fuses
• Shunt for each bridge for monitoring bridge current
• 1600 dc amp bridge, with 1800 amp maximum continuous capability
• No Fans- convection cooled, designed 50° C ambient (See thermal data at left)
• Qty (6) 5700 amp capacity diodes
• 3500 V snubbers for the power semiconductors