Stamford RSK1101 Diode Rectifier Service Kit is responsible for providing power to the Alternator rotor so it can induce voltage to the main windings of a Stamford alternator. 

The RSK1101 Stamford Rectifier Kit is designed to work with P0 / P1 Stamford alternator frames in Stamford BC Series alternators.  Used for Stamford Alternators P044, BC164 and BC184 series. 

Stamford Rectifier Repair Kit RSK1101 includes:

Positive Diodes * 3

Negative Diodes * 3

Surge Suppressor (Varistor) * 1

The diodes on the main rectifier assembly can be checked with a multimeter. The flexible leads connected to each diode should be disconnected at the terminal end, and the forward and reverse resistance checked. (See section 2, diode testing).  The rectifier assembly is split into two plates, positive and negative, and the main rotor is connected across these plates.  Each plate carries 3 diodes, the negative plate carries the negative based diodes, and the positive plate carries the positive based diodes.  Care must be taken to ensure that three identical polarity diodes are fitted to each plate. When fitting the diodes to the plates they must be tight enough to ensure a good mechanical and electrical contact, but should not be over tightened.  The recommended torque tightening is 4.06 to 4.74 Nm, (14 to 17 kg/cm).

The Surge Suppressor (Varistor) in the Stamford Rectifier Kit RSK1101, is a protection device, which prevents high voltage transients from damaging the main rectifier diodes.  High Voltage transients are created by fault conditions in the distribution system. The Voltage transient returns back to the Generator output terminals, enters the main stator windings, and by mutual inductance, is transferred to the main rotor windings, and the main rectifier assembly.

The Surge Suppressor of Stamford Rectifier Kit RSK1001 can be tested with a Multimeter on Megohms range.  A good Surge Suppressor should have a very high resistance, (more than 100 Megohms in either direction).  A faulty Surge Suppressor will be either open circuit (usually showing signs of burning) or short circuit in both  directions. 
The Main Rectifier in the Stamford RSK1001 Rectifier Kit will work normally with this device removed.  However, it should be replaced as soon as possible, to avoid diode failure in the event of further transient fault conditions.   Occasionally, a very high transient may totally destroy the Surge Suppressor. This would result from extreme fault  conditions, such as lightning, (electric storms), close to overhead distribution lines, or out of phase synchronisation of the Generator, when paralleled to multiple Generator systems, (or the Mains, Utility, supply). 

Installation for Stamford Rotating Diode Rectifier

Factory View: