Diagnostic Tests; Introduction; Auto-Off-Manual Switch; Test 42 - Try A Manual Start - Guardian 5240 Diagnostic Repair Manual

Hide thumbs Also See for 5240:

Table of Contents

DC CONTROL

INTRODUCTION

Perform these "Diagnostic Tests" in conjunction with

the "Troubleshooting Flow Charts" of Section 4.3.

The test procedures and methods presented in this

section are not exhaustive. We could not possibly

know of, evaluate and advise the service trade of all

conceivable ways in which testing and trouble diagno-

sis might be performed. We have not undertaken any

such broad evaluation.

TEST 41 - CHECK POSITION OF AUTO-OFF-

MANUAL SWITCH

DISCUSSION:

If the standby system is to operate automatically, the

generator AUTO-OFF-MANUAL switch must be set to

AUTO. That is, the generator will not crank and start

on occurrence of a "Utility" power outage unless that

switch is at AUTO. In addition, the generator will not

exercise every seven (7) days as programmed unless

the switch is at AUTO.

PROCEDURE:

With the AUTO-OFF-MANUAL switch set to AUTO,

test automatic operation. Testing of automatic opera-

tion can be accomplished by turning off the Utility

power supply to the transfer switch. When the util-

ity power is turned off, the standby generator should

crank and start. Following startup, transfer to the

standby source should occur. Refer to Section 1.8 in

this manual.

Following generator startup and transfer to the stand-

by source, turn ON the utility power supply to the

transfer switch. Retransfer back to the "Utility" source

should occur. After an "engine cooldown timer" has

timed out, generator shutdown should occur.

RESULTS:

1. If normal automatic operation is obtained, discontinue

tests.

2. If engine does NOT crank when utility power is turned

off, proceed to Test 42.

3. If engine cranks but won't start, go to Problem 10 in

Section 4.3.

4. If engine cranks and starts, but transfer to "Standby"

does NOT occur, go to Problem 5 in Section 3.3.

5. If transfer to "Standby" occurs, but retransfer back to

"Utility" does NOT occur when utility source voltage is

restored, go to Problem 6 in Section 3.3.

TEST 42 - TRY A MANUAL START

DISCUSSION:

The first step in troubleshooting for an "engine won't

PART 4

crank" condition is to determine if the problem is

peculiar to automatic operations only or if the engine

won't crank manually either.

PROCEDURE:

1. On the generator panel, set the AUTO-OFF-MANUAL

switch to OFF.

2. Set the generator main line circuit breaker to its OFF (or

open) position.

3. Set the generator AUTO-OFF-MANUAL switch to MANUAL.

a. The engine should crank cyclically through it's

"crank-rest" cycles until it starts.

b. Let the engine stabilize and warm up for a few

minutes after it starts.

RESULTS:

1. If the engine cranks manually but does NOT crank auto-

matically, go to Test 43.

2. If the engine does NOT crank manually, proceed to

Problem 9 in the "Troubleshooting Flow Charts".

TEST 43- TEST AUTO-OFF-MANUAL SWITCH

DISCUSSION:

When the AUTO-OFF-MANUAL switch is set to AUTO

position, battery voltage (12 volts DC) is delivered

to the circuit board via Wire 15A, the closed switch

terminal. This voltage is needed to operate the circuit

board.

Setting the switch to its "Manual" position delivers

battery voltage to the circuit board for its operation. In

addition, when the switch is set to "Manual", 12 volts

DC is supplied to the circuit board via Wire 239.

239

15A

A. Set to "Manual"

15A/194

15/15

194/194

15A/15A

239

Figure 1. Schematic of AUTO-OFF-MANUAL Switch

SECTION 4.4