Scotsman NM952 Owner’s Manual

INTRODUCTION

NM952

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 NM952 is a modular ice system that fits a variety of Scotsman ice storage bins.

TABLE OF CONTENTS

Installation

For the Installer

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Two units on one bin . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

For the Plumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

For the Electrician . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Final Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

It features: front service for the freezer, gearmotor, control box, water reservoir, and bin control; an electronic circuit for monitoring ice and water level; a thermostatic expansion valve; and R-22 as the refrigerant.

Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Component Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Electrical Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Maintenance and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Removal and Replacement

Reservoir and Bin Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Bearing and Breaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Auger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Water Seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Evaporator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Fan Motor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Electronic Tester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Parts lists and wiring diagrams are in the center of this manual, printed on yellow paper.

This manual was printed

on recycled paper.

August 1993

Page 1

WATER

INLET

NM952

FOR THE INSTALLER

BACK VIEW: AIR COOLED

WATER INLET

3/8" FLARE

DRAIN

3/4" FPT

Note: Allow 6"

behind and 6"

above either unit

for air circulation,

utility connections,

and service.

ELECTRICAL

INLET

9.5"

5.25"

Condenser Inlet 3/8" FPT

2.1"

5.7"

Condenser Drain 1/2" FPT

BACK VIEW: WATER COOLED

2.9"

3.4"

DRAIN

3/4" FPT

4.9"

7.46"

ELECTRICAL

5.25"

INLET

7.3"

9.43"

The NM952 is designed to fit the following Scotsman storage bins:

B90 and extensions (with bin top KBT18) BH800 using bin top KBT15 (one unit). BH800 (two units, no bin top required). BH900 with KBT24 (one unit) BH900 with KBT25 (two units side by side)

When installing a new system, check to be sure that you have everything you need before beginning:

Correct Bin Correct Ice Machine Correct Bin Top (if required) All kits, legs, and information required for the specific job.

SPECIFICATIONS: ICE MAKER

Model Number

NM952AE-3A

NM952WE-3A

NM952AE-32A

NM952WE-32A

Dimensions

(w/o bin)

W x D x H

21" x 24" x 27"

same same same

Basic

Electrical

208-230/60/3

same

208-230/60/1

same

Installation Limitations:

This ice system is designed to be installed indoors, in a controlled environment:

Min Max

Air Temperature50 Water Temperature 40

F 1000F

F 1000F Water Pressure 20 PSI 80 PSI Voltage -5% +10%

(Compared to the nameplate) Operating the machine outside of the limitations is

misuse and can void the warranty.

The normal finish for the ice machine is enamel-sandalwood. A stainless steel panel kit, SPKFM21 may be field installed to convert the unit to a stainless steel finish.

Ice Type

Nugget

same same same

Condenser

Type

Air

Water

Air

Water

Refrigerant Charge* Air Cooled 32 oz. R-22 Water

28 oz. R-22

Cooled

* Always go by the nameplate charge.

August 1993

Page 2

FOR THE INSTALLER

NM952

Typical Storage Bin with Extension and Bin Top

Location:

After uncrating and inspection, the unit is ready for installation. It is important that the machine be installed in a location where it has enough space around it to be accessible for service, and minimum of 6" be allowed at the back for air circulation on air cooled models. Try to avoid hot, dirty and crowded locations. Be sure that the location for the machine is within the environmental limitations.

Storage Bin:

Tip the storage bin on its back, using parts of the carton to protect the exterior finish. Install the legs into the threaded holes in the bottom of the bin. Turn the leg levelers all the way in preparation for leveling later. Return the bin to the upright position, remove paper covering the bin gasket.

Note: Do not push bin into position, but lift it there. Pushing a bin, especially one with ice in it, can cause damage to the legs and the leg mounts.

Install the appropriate bin top on the bin, according to the instructions for the bin top.

Scotsman Ice Systems are designed and manufactured with the highest regard for safety and performance. They meet or exceed the standards of UL, NSF and CSA.

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 part 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 design are subject to change without notice.

Ice Maker:

The machine is heavy, so the use of a mechanical lift is recommended for lifting the machine high enough to install on top of the bin. After the unit is placed on the bin, line it up so it is even with the back side. Secure the machine to the bin with the hardware provided with the machine.

Remove the front panel and remove any shipping blocks.

August 1993

Page 3

NM952

FOR THE INSTALLER: Location

TWO UNITS ON ONE BIN

ALLOW ROOM

FOR AIR CIRCULATION AND SERVICE

ACCESS

DO NOT STACK ANYTHING IN

FRONT OF THE MACHINE(S)

August 1993

Page 4

FOR THE PLUMBER

AIR COOLED

MODELS

VENTED

DRAIN

CONFORM TO ALL APPLICABLE CODES

NM952

Water Inlet

Air Cooled Models: The recommended water

supply is clean, cold water. Use 3/8" O.D. copper tubing, connect to the 3/8" male flare at the back of the cabinet. Install a hand valve near the machine to control the water supply.

Water Treatment: In most areas, a water filter of some type will be useful. In areas where the water is highly concentrated with minerals the water should be tested by a water treatment specialist, and the recommendations of the specialist regarding filtration and/or treatment should be followed.

Water Cooled Models: A separate 3/8" O.D. copper line is recommended, with a separate hand valve to control it. It is connected to a 3/8" FPT condenser inlet at the back of the cabinet. The

water pressure to all lines must always be above 20 psig, and below 80 psig.

Drains

Air Cooled Models: There is one 3/4" FPT drain

at the back of the cabinet, the drain line is of the gravity type, and 1/4 inch per foot fall is an acceptable pitch for the drain tubing. There should be a vent at the highest point of the drain line, and the ideal drain receptacle would be a trapped and vented floor drain. Use only 3/4" rigid tubing.

Water Cooled Models: In addition to the above mentioned drain, a separate condenser drain must be installed. Connect it to the 1/2" condenser drain connection at the back of the cabinet.

Storage Bin: A separate gravity type drain needs to be run, similar to the air cooled drain. Insulation of this drain line is recommended.

COOLED

HAND

VALVE

WATER

CONDENSER

INLET

WATER

FILTER

CONDENSER

DRAIN

FIELD

SUPPLIED

FILTER

HAND

VALVE

VENTED

DRAIN

WATER

INLET

August 1993

Page 5

NM952

FOR THE ELECTRICIAN

CONFORM TO ALL APPLICABLE CODES

The electrical power to the unit is supplied through the junction box at the rear of the machine.

Check the nameplate (located on the back panel) for the voltage requirements, and for the minimum circuit ampacity. The machine requires a solid chassis to earth ground wire.

WATER COOLED

The ice maker should be connected to its own electrical circuit so it would be individually fused. Voltage variation must remain within design limitations, even under starting conditions.

All external wiring must conform to national, state, and local electrical codes. The use of a licensed electrician is required to perform the electrical installation.

POWER

SUPPLY

AIR COOLED

August 1993

Page 6

FOR THE INSTALLER

NM952

Final Check List

1. Is the ice system installed indoors in a location where the air and water temperatures are controlled, and where they do not exceed the design limitations?

2. Is there an electrical service disconnect within sight of the installed machine? Has the voltage been checked, and compared to nameplate requirements?

3. Have all the plumbing connections been made and checked for leaks?

4. Has the machine and bin been leveled?

5. Is there a minimum of 6" clearance at the back of the machine for proper service access and air circulation?

6. Is the water pressure a minimum of 20 psig?

7. Has the machine been secured to the bin?

8. Is there clearance over the top of the machine for service access?

9. Is there a water shut off valve installed near the machine?

10. Have all of the shipping blocks been removed?

August 1993

Page 7

NM952

START UP

Pre-Start Inspection

1. Remove the front and side service panels.

2. Check that the styrofoam shipping blocks have been removed.

Start Up

1. Go through the prestart inspection.

2. Open the hand valve, observe that water enters the water reservoir, fills the tube from the reservoir to the evaporator, and then shuts off. Check for leaks.

3. Switch the master switch on. The electrical start up sequence is now on

automatic. A. There should be a short (15 second) delay

before the gearmotor starts. B. After the gearmotor starts, the compressor will

start.

3. Inspect the interior of the machine for loose screws or wires. Check that no refrigerant lines are rubbing each other. Check that the fan blade turns freely (air cooled).

4. Check that the unit is installed correctly according to the final check list (page 7).

The air cooled discharge pressure will depend upon air and water temperatures, but should be between 200 psig and 280 psig.

The water cooled discharge pressure should be constant at about 220 psig.

The above numbers are for new, clean machines, you can expect to see some values higher, and some lower between different units.

6. THERE ARE NO ADJUSTMENTS TO MAKE, so replace the panels.

7. Clean and/or sanitize the storage bin interior, wipe off the exterior with a clean, damp cloth.

4. On air cooled models, the condenser will begin to discharge warm air, on water cooled models, the water regulating valve will open, and warm water will be discharged into the drain.

5. The unit should soon be making ice, if desired, the low side pressure may be checked: it should be 25 psig + or - 2 psig.

The suction line temperature at the compressor is normally very cold, nearly to the point of frost up to the compressor body, but not on it.

8. Give the owner/user the service manual, instruct him/her in the operation of the unit, and make sure they know who to call for service.

9. Fill out the manufacturers registration card, and mail it to the Scotsman Factory.

10. Fill out the field quality audit form, and mail it to the Scotsman factory.

August 1993

Page 8

COMPONENT DESCRIPTION

NM952

Control Box: Contains the electrical controls that

operate the machine. High Pressure Cut Out Switch: A manual reset

switch sensing the high side refrigeration pressure. It is set to shut the machine off if the discharge pressure should ever exceed 400 psig.

Evaporator: A vertical stainless steel tube, refrigerated, and water filled. In it there is a stainless steel auger.

Compressor: The refrigerant vapor pump. Reservoir: Float operated, it maintains the water

level in the evaporator at a constant level, it also contains the water level sensor.

Water Level Sensor: Senses if there is water in the reservoir to make ice out of. Will shut the machine off it there is none.

AIR COOLED

Ice Discharge Chute: Directs the ice produced by the evaporator into the storage bin.

Ice Level Sensor: An electronic "eye", it senses the presence of ice in the bottom of the ice discharge chute. Operates to turn the ice machine on and off automatically as the level of ice in the bin changes.

Gear Motor: An oil filled, speed reduction gearbox, driving the auger.

Drain Tube: When uncapped and lowered, drains the evaporator.

Condenser: Air or water cooled, where the heat removed in ice making is discharged.

Expansion valve: The refrigerant metering device.

WATER COOLED

ICE CHUTE

CONTROL BOX

CONDENSER

EXPANSION

VALVE

RESERVOIR

DRAIN

TUBE

CONTROL BOX

CONDENSER

EXPANSION

VALVE

RESERVOIR

ICE CHUTE

COMPRESSOR

ICE LEVEL

SENSORS

August 1993

Page 9

HIGH

PRESSURE

CUT OUT

ICE LEVEL

SENSORS

NM952

COMPONENT DESCRIPTION: Control Box

Contactor: A definite purpose contactor connecting the compressor and the remote condenser fan motor to the power supply.

Circuit Board: Controlling the ice machine through sensors and relays. The sensors are for 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 compressor.

ON/OFF SWITCH

LOW

PRESSURE

CUT OUT

SWITCH

Transformer: Supplies low voltage to the circuit

board. Low Pressure Cut Out Switch: A manual reset

control that shuts off the ice machine when the low side pressure drops below a preset point, 0-4 psig.

Potential Relay: The compressor start relay. On/Off Switch: Manual control for the machine.

POTENTIAL

RELAY

TRANSFORMER

CIRCUIT

BOARD

CONTACTOR

August 1993

Page 10

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