Generac Power Systems 53187 - Manual (Page 111)

PARTS
ENGINE ELECTRICAL SYSTEM
1
SECTION 5.2
ENGINE CRANKING SYSTEM
Section 5.2
ENGINE CRANKING SYSTEM_____________
2. When ambient temperature is below 32’ F. (O’ C.),
use a 12 volts storage battery rated 95 amp-hours and
having a cold cranking capacity of 450 amperes. Introduction
As explained in Section 5.1, the generator may incor­
porate any one of several different DC control systems.
These systems were arbttraiily designated as Type 1,
Type2 orType 3. The engine cranking system Is a part
of the DC control system. Each designated type will be
discussed sepsirately In this section. You may wish to
familiarize yourself with the operation of each type by
reading Section 5.1, "Introduction to DC Control Sys­
tems’.
Battery Cables: Use of battery cables that are either
too long or too small In diameter will result In excessive
voltage drop. For best cold weather starting, voltage
drop between the battery and the starter should not
exceed 0.12 volts per 100 amperes of cranking current.
Select the cables based on its length as recommended
in the following chart:
Type 1 Engine Cranking System
GENERAL:
The Type 1 engine cranking system was used in
conjunction with early production engine control circuit
boards. The system incorporates a crank relay (CR1)
which, when energized by setting the start/stop switch
to "Start", deiivers battery voitage to the engine control
circuit board. The energized circuit board then delivers
battery voltage to a starter contactor (SC) coil (via a Wire
56 circuit). The starter contactor’s normally-open con­
tacts close to deliver battery power directly to a starter
motor and the engine cranks.
COMPONENTS:
The following components are part of the Type 1
engine cranking system:
DThe 12 volts battery.
Dio amp circuit breaker (CB3).
□l4ampfuse (FI).
□crank Relay (CR1).
□Engine Control circuit board.
□start/Stop switch.
□starter contactor (SC).
□starter (S).
□interconnecting wires.
THE BATTERY:
Recommended Battery: The battery used should be
selected based on the following criteria:
1. When anticipated ambient tempreratures will be con­
sistently above 32' F. (O' C.), use a 12 volts automotive
type storage battery rated at 70 amp-hours and capable
of delivering 360 cold cranking amperes.
CABLE LENGTH*
(IN FEET) RECOMMENDED CABLE SIZE
0-10 No. 2
11 -15 No.O
16-20 No. 000
• Distance from battery post to connection point on
generator.
Performing a Battery Capacity Test: The battery
can be tested using a capacity tester, as shown in Figure
1. To test the battery, proceed as follows:
1. With the battery connected to tester as shown,, turn
the load knob until a current draw equal to three (3) times
the battery rating is selected. For example, if the battery
is rated 70 amp-hours, set the load to 210 amps.
Figure 1. Battery Capacity Test
PAGE 5.2-1