Service manual

Electrical Service Manual V4.0
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CENTRAL COMMAND I
DOWN PRESSURE GAUGE
The scrubbers that were equipped with Central Command 1 used an
active down pressure readout. This readout would convert the amp
draw of the brushes into brush deck pressure and show it on the con-
trol panel mounted brush pressure gauge. For this to work it utilized
the down pressure gauge, a control module and a shunt. The shunt
is wired in series with the brush deck motor(s). When the brush deck
is turned on the control module calculates the down pressure from the
millivolt signal it receives from the shunt. The module then displays the
down pressure relative to the amp draw on the control panel display.
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DOWN PRESSURE GAUGE DIAGNOSIS
The down pressure gauge system is quite simple. The Shunt being a primarily mechanical
device rarely fails. If a gauge flickers or is inoperative the gauge/control module must be
replaced. The gauge and control module are a set and must be replaced as one.
VACUUM SYSTEM DIAGNOSIS
GENERAL DIAGNOSIS
The vacuum systems on the Central Command II scrubbers came either with or without a
vacuum delay timer depending on the model. The following is a list of which models were
manufactured with a timer
Models with a timer: 38, 40, 51, 290, 350, 3700, 5100 & (29,35 built after August 2000)
DOWN PRESSURE GAUGE
ELECTRICAL SHUNT