Scotsman MAR1400 - Manual (Page 23)

MAR Split - Electrical / Refrigeration
I. Strainer Filter
There is a strainer in the liquid line to prevent the
expansion valve from becoming clogged with
debris.
L. Motor Shaft Pulley
MAR Split units are generally equipped with “Step
pulley” and by changing the belt from one groove
to the other the speed of drum can be changed.
The motor pulley must be reversed and the belt
re-tightened to change speeds.
MAR1400 machines are factory delivered with V
belt on smaller dia V groove of step pulley to rotate
the evaporator drum at the lowest possible R.P.M.
to obtain “THICK” (2 m/m or 5/64” thick) scale ice.
Normal drum R.P.M.s for “THICK” ice production
are:
MAR1400 - 1.5 RPM
MAR2000 – 2.4 RPM
M. V Belt
V belts used on motor shaft pulley and gear box
are type Z 33
When changing the V belt from one groove to
another, be careful to adjust it for proper tension
and alignment. It should be snug not tight. A way
to roughly check belt tension is to apply a firm
hand pressure in the middle of the longest belt
span. If the belt is correctly tensioned, you should
be able to depress it about 5 m/m (3/16”) out of
line.
N. Gear Reducer
The gear reducer is mounted to the side frame of
the evaporator drum basin. The gear reducer bore
in which passes the drum shaft to be driven, has a
key way.
Two fiber keys are used to engage the gear
reducer to the drum shaft, they are in line in the
gear reducer bore and shaft key ways.
Should the driving strain be excessive, the two
fiber keys will shear.
Both the MAR1400 and the MAR2000 are
equipped with a gear reducer having a ratio of
1/570.
The gear reducers are greased for life, therefore
they do not require any maintenance.
O. Water pump / spay bar
Used only on FRESH WATER version the water
pump is mounted on the rear left side of
evaporator drum basin.
It supplies water under gentle pressure to the
spray bar located on top of evaporator drum.
Amp draw of the pump during normal operation is
.3 amps.
MAR2000 has an additional spray bar at the front
of the evaporator drum.
P. Ice Level Control – Bin Thermostat
Note: It is subject to corrosion in marine
applications. Mounted in the control box. Must be
deployed at the time of installation.
R. Master Relay or Contactor
With electric coil connected in series with safety
controls for operation in safe conditions of
condensing and evaporating unit. Mounted in the
control box.
T. Time Delay Relay
The relay must be energized for about 10 minutes
before it will actuate its contacts and power the
liquid line valve (which will start the compressor on
dedicated condensing units) and the evaporator
drive motor.
This type of relay prevents compressor and
evaporator drive motor short cycling which could
be harmful to evaporator drive mechanism due to
ice skin being formed on the evaporator drum
jacket that get thicker and sticker during
evaporator drive motor off-momentum. Mounted in
the control box.
V. Liquid Line - Solenoid Valve
Stops refrigerant flow when not desired. Located
on the liquid line, it is electrically connected to the
contactor or relay to stop flooding the evaporator
and suction side during compressor off periods.
MAR1400 & MAR2000
December 2000
Page 23