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Diode Fail Detector

The Stamford Diode Failure Detector senses ripple current in an exciter's output to provide indication of failed diodes. It has a 7 second delayed response and voltage free contacts to signal faults. Receiving early warnings allows planned generator maintenance to replace diodes before damage occurs.

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193 views2 pages

Diode Fail Detector

The Stamford Diode Failure Detector senses ripple current in an exciter's output to provide indication of failed diodes. It has a 7 second delayed response and voltage free contacts to signal faults. Receiving early warnings allows planned generator maintenance to replace diodes before damage occurs.

Uploaded by

Anonymous yugocxn
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© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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Diode Failure Detector

The Stamford Diode Failure Detector (DFD) is suitable for use TECHNICAL SPECIFICATION
with all Stamford Generators. It senses the level of ripple current
in the exciter output to provide indication of a failed diode, either SUPPLY VOLTAGE DC 12-28V
short or open circuit. AC 100 - 140V
or 200 - 280V
Frequently demanded in the oil and gas industries this warning
device is increasingly required by many other users who SUPPLY CURRENT DC 0.2A max
recognise the benefits of early failure warning. The DFD has a
delayed response of 7 second to avoid ‘nuisance trip’ signals OUTPUT Voltage Free Contacts
before indicating the fault via voltage free changeover contacts. Isolation 2kV
1 Pole Changeover
Rating 5A @ 30Vdc/240 ac
By receiving a quick warning of a single failed diode the user
may arrange shutdown (manually or automatically) of the REPONSE TIME (Approx) 7 seconds
engine. Alternatively on receipt of the warning, the exciter
field current or voltage can be monitored, reducing load if ENVIRONMENTAL
necessary, to ensure that recommended levels are not
exceeded. In this way the generator set can continue to provide Operating temp - 40°C to + 70°C
emergency supplies until a planned controlled shutdown when Storage temp - 55°C to + 80°C
the necessary diode replacements can be made. Humidity 0 to 60°C 95%RH
Vibration 20 - 100 Hz 30mm/seconds
Of course a Stamford Series 3 separately excited system offers 100 Hz - 2kHz 2.0g
the safety of over-excitation protection within the AVR. But the
DFD actually diagnoses if the fault lies with the rectifier diodes, Not suitable for mounting in generator terminal box. Switch-
and so encourages the best course of action. board or bedplate mounting recommended.

● Reliable solid-state warning of rotating rectifier diode


failure.

● Jumper Selectable D.C. (12 or 24V) or


AC (120 or 240V).

● Simple connections to generator.

● Simple test facility.


GENERAL ARRANGEMENT DIAGRAM

CONNECTION DIAGRAM

N/3/X/023ED1E © Newage International Limited 1996

NEWAGE INTERNATIONAL LIMITED


Registered Office and Address:
PO Box 17, Barnack Road, Stamford, Lincolnshire PE9 2NB England.
Telephone: 44 (0) 1780 484000 Fax: 44 (0) 1780 484100 Telex: 32268 Registered in England No. 441273

PRINTED IN ENGLAND

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