Figure 26. Trailer mounted DE generator set PU-407/M, ready for operatian.

TM 5-6115-376-13

Figure 26. Trailer mounted DE generator set PU-407/M, ready for operatian.

contactor S3 must be actuated to complete a cur-

assembly through power input receptacle, voltage

rent through power output receptacle or load

is applied through synchronizing bypass switch

cable interconnecting switchbox receptacle to the

S2, across terminals 6 and 7 of terminal load

load. This is accomplished by the following:

TB1, across resistor R2, through transformer Tl,

(a) When power is applied to load through

rectifiers CR1 through CR4, and resistor capacitor

(RC) network consisting of resistor R3 and ca-

power input and power output receptacle from

pacitor Cl, and is applied to the solenoid of

a single power source, synchronizing switch S1

is closed to apply power to one side of the solenoid

control relay K2, as shown in figure 2-8. When

of magnetic contactor S3 and auxiliary relay K1.

power is applied to the synchronizer assembly

The solenoid current is completed through con-

through load cable interconnecting switchbox

tacts 3 and 4 of de-energized control relay K2.

(the synchronizer assembly) receptacle, 3-phase

power is applied through safety circuit breaker

Control relay K2 is deenergized by activating syn-

chronizing by-pass switch S2. When auxiliary

CB1 and power output receptacle to load cable.

relay K1 is energized, one pair of contacts com-

A voltage is also applied across terminals 1 and

pletes the governor current (c below) of the diesel

2 of terminal board TB1, across resistor R1

engine generator sets and the other set of contacts

through transformer Tl, rectifiers CR1 through

short contacts 3 and 4 of control relay K2. When

CR4, and RC network R3 and Cl, to solenoid of

synchronizing by-pass switch S2 is released, con-

control relay K2 and safety circuit breaker. Light

DS1 glows to indicate presence of power at load

tacts of auxiliary relay K1 hold auxiliary relay

K1 and magnetic contactor S3 energized.

cable interconnecting switch box receptacle (or

(b) When power is applied to load through

synchronizer assembly).

(3) Magnetic contractors S3. When power is

p o w e r input, the load cable interconnecting

switchbox, and power output receptacles from two

applied to the synchronizer assembly through

power sources, the electronic synchronizer assem-

power input receptacle ((2) above), magnetic

2-8