Generac 86640 - Manual (Page 53)

Section 4.1- COOLING SYSTEM FAMILIARIZATION
Introduction
The generator cooling system is of the closed recovery
type. Major cooling system components consist of (a) radia­
tor, (b) coolino fan, (c) coolant recovery bottle, (d) engine
water pump, (e) thermostat, and (f) interconnecting hoses.
Recreational vehicle generators are typically housed in
a compartment. An adequate flow of cooling, combustion and
ventilating air must be provided for these compartments.
Some models are equipped with unit-mounted radiators.
Other models may have remote mounted radiators.
At least one IM (Industrial Mobile) generator model is
equipped with a heat recovery system.
Recommended Coolant
Recommended Is a 50-50 mixture of low silicate ethylene
glycol base anti-freeze and soft water for all-weather protec­
tion. If desired, a high quality rust inhibitor may be added to
the recommended mixture. When adding coolant to the radi­
ator or to the coolant r4ecovery bottle, always add the recom­
mended 50-50 mixture.
NOTE: Cooling system capacity for models with unit-
mounted radiator Is approximately 2.5 U.S. gallons (9.5
liters). Use only SOFT water and LOW SILICATE anti­
freeze. For Installations equipped with a remote-mounted
radiator, cooling system capacity will depend on radiator
hose lengths.
The switch contacts should close and switch should read
“continuity“ at about 225‘-235’ F. (107'-113‘ C.).
CAUTION: The use of any "chromate" base Inhib­
itor is NOT recommended. When chromate base
rust inhibitor is used with ethylene glycol base
anti-freeze, chromium hydroxide Is formed in the
cooling system. Chromium hydroxide Is visible to
the eye as a "green slime" which can cause re­
duced heat transfer and possible overheating. Any
cooling system that has been operated with a
chromate
base inhibitor must be chemically
cleaned before adding ethylene glycol base anti­
freeze. Use of any high silicate anti-freeze boost­
ers or additives is NOT recommended. In addition
to the preceding, the use of any soluble oil rust
inhibitor Is NOT recommended.
High Coolant Temperature Switch
DESCRIPTION:
The engine mounts a normally-open (N.O.) thermostatic
switch (Figure 1). The sensing tip of the switch is normally
immersed in engine water jacket coolant. Should coolant
temperature exceed approximately 230' F. (110* C.), the
switch contacts will close and the engine will shut down
automatically.
TESTING HIGH TEMPERATURE SHUTDOWN:
To test the high temperature shutdown feature, first
disconnect Wire No. 85 from the switch terminal. Start the
engine, let it stabilize and warm up at no-load. Hold the
terminal end of Wire No. 85 into contact with a clean frame
ground on the engine. After a short delay, the engine should
shut down.
TESTING THE SWITCH:
Remove the switch. Check the switch closing tempera­
ture with an ohmmeter (Figure 2).
Page 4,1-1