Scotsman NM1850RH User manual

TO THE OWNER OR USER:
The service manual you are reading is
intended to provide you, and the maintenance
or service technician, with the information
needed to install, start up, clean, maintain and
service this ice system.
The NM1850RH (remote high side) is the
freezer portion of a commercial ice machine. It
is designed to be connected to the
condensing section of a refrigeration system,
specifically a supermarket R-502 system. It
consists of two evaporators, two gearmotors,
two liquid line valves, two control boxes, two
thermostatic expansion valves, and an EPR
valve.
TABLE OF CONTENTS
For the Installer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
For the Electrician . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4
For the Plumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 5
Final Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6
Initial Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 7
Component Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8
Electrical Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 11
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 12
Maintenance and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 14
Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 17
Removal and Replacement
Bin Controls and Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 20
Bearing and Breaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 21
Auger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 22
Water Seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 23
Evaporator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 24
Gearmotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 25
Circuit Board Tester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 26
Parts lists and wiring diagrams are in the center of this manual, printed on yellow paper.
NM1850RH
May, 1989
Page 1

FOR THE INSTALLER: Specifications
The NM1850RH is designed to fit the
Scotsman storage bin B590 and the BX560
extension. Leg kit KLP4 is recommended
when using both the bin and the extension.
Installation Limitations: The NM1850RH is
designed for indoor installations only. The
machine must also be in a controlled
environment where the air temperature does
not fall below 500F., or go above 1000F.
The water temperature must be between
400F. and 1000F.
The electrical power supply must not drop
below -5% of the lowest nameplate voltage or
go above 10% of the highest nameplate
voltage.
SPECIFICATIONS:
Scotsman Ice Systems are designed and
manufactured with the highest regard for
safety and performance. They meet or
exceed the standards of U.L., N.S.F., and
C.S.A.
Scotsman assumes no liability or responsibility
of any kind for products manufactured by
Scotsman that have been altered in any way,
including the use of any parts and/or other
components not specifically approved by
Scotsman.
Scotsman reserves the right to make design
changes and/or improvements at any time.
Specifications and designs are subject to
change without notice.
NM1850RH-32A 27" X 42" X 24" NUGGET 208-230/60/1
2.7
15
16,000
Model Number Dimensions (w/o Bin)
H" x W" D" Ice Type Basic Electrical
Minimum
Circuit
Ampacity
Maximum
Fuse
Size
BTU’s
Required
15.53"
3.1"
SUCTION LINE CONNECTION 7⁄8"
LIQUID LINE CONNECTI0N 1⁄2"
20.84"
9.43"
5.25" 3"
17.8"
18.8"
21.66" ELECTRICAL INLET
POTABLE WATER INLET 3/8" FLARE
DRAIN 3/4" FPT
BACK VIEW
NM1850RH
May, 1989
Page 2

FOR THE INSTALLER
Select the Location:
The unit can only be installed
indoors within the limitations
described on page 2.
The ice machine will have to be
connected to the buildings R502
refrigeration system, check to be
sure that the system has enough
extra capacity to handle a
minimum of additional 16,000
BTU’s per hour @ 1100F. liquid
line temperature. (Assume a
100F. evaporator temperature.
Storage Bin:
Scotsman’s B590 will be the
presumed bin of choice. If using
the bin extension BX560, install
heavy duty leg kit KLP4 and place
the bin into position.
Remove the paper tape from the
bin edge gasket, and install the
bin extension onto the B590.
Remove the paper tape from the
bin extension top edge, and using
a mechanical lift, install the
NM1850RH onto the top of the
storage bin assembly.
Fasten the ice machine to the bin
using (4) 5/15-18 2.5" cap screws.
Level the assembly by:
a. Turning the leg levelers in or
out on the standard legs.
b. Use shims under the heavy
duty legs of the KLP4.
Locate the Nameplate: The
nameplate is located on the back
panel of the machine, and
contains the electrical characteristics
particular to the unit being installed.
Refrigeration Installation:
The skills of a refrigeration technician are
required to connect the ice machine to the
buildings refrigeration system.
//////////////////////////////Caution/////////////////////////////
Connect to a R502 system only.
////////////////////////////////////////////////////////////////////////
Local Codes must be observed.
A P-trap should be installed where there will
be more than 10’ of vertical rise in the suction
line.
TYPICAL INSTALLATION: ALLOW ROOM FOR SERVICE ACCESS
NM1850RH
B560 BIN
EXTENSION
B590 STORAGE
BIN
NM1850RH
May, 1989
Page 3

FOR THE ELECTRICIAN
CONFORM TO ALL APPLICABLE CODES
Electrical Connections:
Locate the nameplate for the
current requirements, and then
determine the wire size and type
per the National Electric Code. The
machine requires a solid chassis to
earth ground wire. Refer to the
wiring diagram. The ice machine
should be connected to it’s own
electrical circuit, and be individually
fused.
Voltage, when the unit is under full
load, must remain within the
limitations listed on page 2.
LOW VOLTAGE CAN CAUSE
EQUIPMENT MALFUNCTION
AND/OR DAMAGE
All external wiring should conform
to the National, State, and local
electrical codes. Usually the
services of a licensed electrician
will be required.
DETAIL OF
JUNCTION BOX
JUNCTION
BOX
POWER SUPPLY
NM1850RH
May, 1989
Page 4

FOR THE PLUMBER
CONFORM TO ALL APPLICABLE CODES
Water Supply:
The recommended water supply line is 3/8"
O.D. copper tubing, with a minimum operation
pressure of 20 PSIG, and a maximum of 120
PSIG. Connect to cold water using the male
flare connection at the back of the machine.
Install a shut off valve in an accessible space
between the ice maker and the water supply.
Drain System:
All drains are of the gravity type, and must
have a minimum of 1/4" fall per foot of
horizontal run. The drains must be installed to
conform to local plumbing codes. The use of a
vent at the machine and at the bin will allow
the system to drain properly. Use only rigid
tubing for drains; insulation of the bin drain is
recommended.
SHUT OFF
VALVE
FIELD
SUPPLIED
WATER FILTER
3/8" MALE FLARE
3/4" FPT
VENT THIS DRAIN
WATER INLET
BIN DRAIN
FLOOR DRAIN
NM1850RH
May, 1989
Page 5

FOR THE INSTALLER: Final Check List
1. Is the unit installed where the air and water
temperatures are within and will remain within
the limitations for the unit?
2. Is there 6" clearance at the rear of the
machine for utility connections?
3. Has the water supply line be checked for
pressures between 20 and 120?
4. Has the unit been leveled?
5. Has the shipping material been removed
from inside the cabinet?
6. Have the electrical connections been made?
7. Have the drains been installed and checked
for leaks?
8. Has the refrigeration supply been installed
and checked for leaks?
9. Has the bin and cabinet been wiped clean
or sanitized?
10. Has the warranty registration card been
properly filled out and mailed to Scotsman?
11. Has the owner been given the service
manual and been instructed on how to
maintain the icemaker?
13. Has the owner been given the name and
telephone number of the local Scotsman
service agency?
NM1850RH
May, 1989
Page 6

INITIAL START UP
1. Remove the top and front panels.
2. Open the water valve, and observe that the
two float reservoirs fill up with water and shut
off.
3. Switch on the electrical power.
4. Open the hand valves (in the liquid lines).
5. Open the ball valves (in the suction lines).
6. Switch on one master switch, and observe:
The liquid line valve opens
The gearmotor runs
Within a short time, that side of the machine
begins to make ice.
Water flows from the water reservoir, and the
float drops, letting in more water.
7. Switch on the other master switch, observe
that:
The liquid line valve opens
The gearmotor runs
Within a short time, that side of the machine
begins to make ice.
Water flows from the water reservoir, and the
float drops, letting in more water.
8. With both sides operating, the sight glass
should remain full, and the low side pressure
will be about 30 psig, + or - 4 psig. Gearmotor
amp draw should not exceed the nameplate
rating.
9. Check the system very carefully for any
refrigerant leaks, repair as needed.
NM1850RH
May, 1989
Page 7

COMPONENT IDENTIFICATION
Liquid line valve(s)
These valves operate to turn the ice making
process on and off.
When the ice level drops in the ice chute, the
ice level sensor will cause the circuit board to
close the liquid line relay, which energizes the
liquid line valve for that side of the system.
The liquid line valve opens, and liquid
refrigerant flows to the thermostatic expansion
valve.
Thermostatic Expansion Valve
The metering device of each system, the
valve(s) sense the temperature of the suction
line and vary the amount of liquid refrigerant
that passes through the valve into the
evaporator, thus maintaining a constant level
of refrigeration. TXV’s are factory set. Do not
adjust unnecessarily.
DO NOT ADJUST THE TXV UNTIL THE EPR
HAS BEEN SET.
The superheat setting is 4-80F. Measure the
temperature of the evaporator outlet at the
TXV bulb, and check the low side pressure at
the EPR valve. Convert the pressure to
temperature (using a temperature pressure
chart) and subtract the amount from the outlet
temperature. The result is the superheat. Use
an electronic thermometer.
EPR: Evaporator Pressure Regulator Valve
This valve maintains a constant pressure on
it’s inlet (evaporators) side regardless of the
pressure on the outlet (suction) side. The EPR
is factory set, adjust only if needed. After
adjusting check TXV superheat.
Evaporators:
Where the water is frozen into ice crystals. As
the water cools, it begins to turn into ice, and
the slowly turning auger lifts the ice, as it is
being made, and forces it up and out of the
"breaker" or spout where the extra water is
compressed out of the ice. The ice then drops
through the chute, into the storage bin.
LIQUID LINE
VALVE
THERMO VALVE EPR VALVE THERMO
VALVE
EVAPORATOR
NM1850RH
May, 1989
Page 8

COMPONENT DESCRIPTION: Control Box
Circuit Board: Controlling the ice machine
through sensors and relays. The sensors are:
ice level, and water level. The relays are for
the gear motor (with a built in time delay to
clear the evaporator of ice when the unit turns
off) and for the liquid line valve.
Transformer: Supplies low voltage to the
circuit board.
On/Off Switch: Manual control for that side
of the machine.
Reset Switch: Manual reset. Glows when
the unit shuts off from the ice discharge chute
being overfilled (pressure of the ice opening
the microswitch at the top of the chute).
ON/OFF SWITCH
TRANSFORMER
CIRCUIT
BOARD
TERMINAL STRIP
RESET SWITCH
NM1850RH
May, 1989
Page 9

COMPONENT DESCRIPTION: Evaporator
Evaporator: A refrigerated vertical tube filled
water and containing a water seal and auger.
Auger: A solid stainless steel double spiral
auger, it pushes the ice crystals up to the top
of the evaporator.
Water Seal: A two part "face" seal, the top
half rotating with the auger, the bottom half
stationary, the sealing action being where the
two seal "faces" meet.
Ice Sweep: A plastic cap with "fingers". It
revolves with the auger to "sweep" the ice into
the ice chute.
Divider: Where the ice is compressed and
much of the extra water is squeezed out of it
before it is discharged into the bin.
Motor: A permanent split capacitor motor that
drives the gear reducer.
Bearing: As the ice is pushed up the
evaporator, the auger is thrust down, and
pressure from the auger thrust is taken up by
this bearing.
BEARING ICE SWEEP
DIVIDER
EVAPORATOR
AUGER
WATER
SEAL
MOTOR
NM1850RH
May, 1989
Page 10