Utility Source Voltage Available - Guardian 5240 Diagnostic Repair Manual

Hide thumbs Also See for 5240:

Table of Contents

SECTION 3.2

OPERATIONAL ANALYSIS

Figure 3 is a schematic representation of the transfer switch with utility source power available. The circuit condi-

tion may be briefly described as follows:

• Utility source voltage is available to terminal lugs N1 and N2 of the transfer mechanism, transfer switch is in the

UTILITY position and source voltage is available to T1, T2 and customer load.

• Utility source voltage is available to limit switch (XA1) via the normally-closed transfer relay contacts (1 and 7)

and Wire 126. However, XA1 is open and the Circuit to the utility closing coil is open.

• Utility voltage "sensing" signals are delivered to a circuit board on the generator, via Wire N1A, a 5 amp fuse

(F1), transfer switch Terminal N1, generator Terminal N1 and a sensing transformer. The second line of the util-

ity voltage "sensing" circuit is via Wire N2A, a 5 amp Fuse (F2), transfer switch Terminal N2, generator Terminal

N2, and the sensing transformer.

N1A

126

N1A

126

COM

VR1

N2A

ATS

N2A

LEGEND

ATS-AUTOMATIC TRANSFER SWITCH

C1-UTILITY COIL & RECTIFIER

C2-GENERATOR COIL & RECTIFIER

F1,F2-5A, 600V FUSE

LC-CIRCUIT BREAKER (LOADS)

TR-TRANSFER RELAY

TS-TERMINAL STRIP

XA,XB-LIMIT SWITCHES

Page 56