Thermo Scientific Harris MBF-700 User manual

Installation and Operation Manual
Thermo Scientific®Harris MBF-700
Refrigeration System

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All other trademarks are the property of Thermo Fisher Scientific Inc. and
its subsidiaries.

Table of Contents
Thermo Fisher Scientific Generic MBF700 Service Manual i
Table of Contents
Section 100 – Product Introduction .............................................. 1
Freezer Overview ........................................................................... 1
General Construction .................................................................... 2
Control Panel ............................................................................... 3
Liquid CO2 (LCO2) Backup System .......................................... 4
Section 200 – Installation And Operation ..................................... 17
Installation Check List ................................................................... 17
Operator's Responsibilities ............................................................ 17
Water-cooled Condensing Unit Connections ............................. 19
Cleaning The Freezer Surfaces ....................................................... 21
Storage .......................................................................................... 21
Section 300 – Theory Of Operation .............................................. 22
Overview ....................................................................................... 22
Sequence Of Operation ................................................................. 22
Systems Description ...................................................................... 23
Refrigeration Systems .................................................................. 23
Safety Devices ............................................................................. 24
Temperature Control .................................................................. 24
LCO2 Backup System ................................................................ 25
Halo Passes ................................................................................. 26
Operation ...................................................................................... 26
Cascade Refrigeration System ..................................................... 26
Main Temperature Control ........................................................ 27
Backup Temperature Control System ......................................... 29
Section 400 – Maintenance And Service ........................................ 31
Preventive Maintenance Procedures .............................................. 31
Air Cooled Condensers ............................................................... 31
Compressor Oil Level ................................................................. 31
fan Motors .................................................................................. 31
Defrosting ................................................................................... 31

Table of Contents
ii Generic MBF700 Service Manual Thermo Fisher Scientific
LCO2 Vent ................................................................................ 32
Trouble Shooting Guide ............................................................... 32
Contactors And Relays ................................................................ 39
Compressor Motors, Three Phase ............................................... 39
Partial Or Complete Loss Of Refrigeration ................................. 40
Checking Refrigerant Charge ...................................................... 40
Installing Gauges ........................................................................ 41
Leak Testing, Repairing And Charging – An Overview ............... 41
Repair Procedures .......................................................................... 43
Compressor Replacement ............................................................ 43
Backflush Procedure ................................................................... 46
Evacuation Procedure ................................................................. 48
Charging Procedure -- 1st (High) Stage ...................................... 51
Charging Procedure -- 2nd (Low) Stage ...................................... 51
Thermocouple Labeling And Locations ...................................... 53
temperature Calibration .............................................................. 53
Section 500 – Appendix ................................................................ 55
Refrigeration System Data ............................................................ 56
Service Parts List ........................................................................... 57

SECTION 100 – PRODUCT INTRODUCTION
Thermo Fisher Scientific Generic MBF700 Service Manual 1
SECTION 100 –
PRODUCT
INTRODUCTION
FREEZER OVERVIEW This unit is a low temperature freezer designed to operate with a chamber
temperature in the range of –65 to –85 °C (-85 to –121 °F) and in an
ambient temperature range of 15 to 32 °C (59 to 89.6 °F).
The cabinet configuration is that of a rectangular solid measuring 121” long
(3 07.3cm) x 47.5” high (120.7cm) with lid and all covers in place x
35.312” deep (89.7cm). When installing the freezer, a minimum of six
inches (6”) must be provided on all sides of the freezer for proper air
circulation.
Weight is 1510 lbs. (684.8Kg) net.
Shipping weight is 1790 lbs (811.8Kg).
Power Requirements: 208V - 230VAC, 3 Phase , 60Hz
120VAC, 1 , 60Hz (LCO2 backup system)
Figure 1. General Freezer Outline (see Figure 3 for control panel
details)
The interior useable space is also rectangular. The four corners are coved.
With insulating sub lids in place it measures 71” long (180.3cm)x 35.37”
high (89.9cm) x 22.63” deep (57.5cm). The interior volume is 31 Ft.
(878.7 liters.)
The cabinet is insulated with nominal 5” of foamed-in-place polyurethane
insulation.

SECTION 100 – PRODUCT INTRODUCTION
2Generic MBF700 Service Manual Thermo Fisher Scientific
CAUTION Do not discard the sub lids. They are necessary for the
operation of the unit.
The refrigeration arrangement employed in this freezer is a specially
designed assembly using four hermetic motor compressors. This design is
termed a “redundant cascade system”. A more complete description of this is
in the pages following. Stainless steel storage racks for inventory control are
avaiable as an option and must be ordered separately.
GENERAL
CONSTRUCTION The lid is held tightly closed by means of cam locks having provision for a
user supplied padlock.
Durable corrosion protection is provided by an electrostatically applied
epoxy fused powder coating over cold rolled steel.
To provide a redundant refrigeration system, the inner tank is double
wrapped with copper tubing forming a dual circuit evaporator. In addition,
each of these circuits has its own compressor, condenser and liquid
refrigerant control (capillary tube). Each of the redundant systems will
support full operation to maintain the storage temperature. When set to
alternate between system “A” and system “B”, refrigeration is applied to the
freezer chamber alternating between systems on each cycle.
Figure 2. Cabinet Dimensional Drawing

SECTION 100 – PRODUCT INTRODUCTION
Thermo Fisher Scientific Generic MBF700 Service Manual 3
CONTROL PANEL All controls are located at the right end of the cabinet
Figure 3. Control Panel Detail
1. Key-operated alarm ON/OFF switch. Turns on local audio alarm.
2. Key-operated compressor ON/OFF switch. Turns on power to
compressors and control system.
3. Digital temperature indicator and primary control
4. Temperature recorder, 7-day, 6” diameter.
5. System “B” indicator light. “ON” when system “B” 1st stage
running.
6. System “A” indicator light. “ON” when system “A” 1st stage
running.

SECTION 100 – PRODUCT INTRODUCTION
4Generic MBF700 Service Manual Thermo Fisher Scientific
7. Alternate system alarm indicator light. “ON” when auxiliary control
causing both systems to operate.
8. Heater switch. Operates breaker strip condensate heater.
9. Battery meter. Displays state of battery charge when button is
pressed.
The remote alarm contacts were developed to provide an alert for an alarm
condition. The remote alarm contacts are normally closed, and open during
an alarm event. The contacts are rated for a maximum of 36V3A
LIQUID CO2 (LCO2)
BACKUP SYSTEM When connected to a user supplied siphon tank of liquid CO2, the backup system will provide a source of backup refrigeration in case of power failure
to the mechanical refrigeration equipment. The control assembly operates
on 1 20VAC, 1, 60Hz. A backup battery supply is continuously charging for
operation of the backup system during power failure.
Installation
1. Place the LCO2 control system on top of the System B mechanical
section.
2. Connect the LCO2 supply to the back of the control system.
3. Connect theLCO2 distribution tube to the back of the unit.
4. Connect the LCO2 temperature sensor to the Mate-N-Loc
connector that hangs from the rear of System B mechanical section.
5. Connect the LCO2 control system harness to the Mate-N-Loc
connector that hangs from the rear of System B mechanical section.
6. The assembly of the LCO2 to the cabinet is now complete.
Note An LCO2 supply must be provided by the customer. The supply
pressure must be 900 – 1,000 PSIG.

SECTION 100 – PRODUCT INTRODUCTION
Thermo Fisher Scientific Generic MBF700 Service Manual 5
7. Uncoil the tubing from the control unit and connect to the LCO2
tank or supply connection.
8. Turn on the LCO2 valve.
9. Refer to the Backup System Owners Manual for operation
instructions.
Note LCO2 backup systems are typically built with a relief valve set for
1,300 PSIG.
LCO2 Control System Battery Condition
The charge level light illuminates when the battery is below 80% of full
charge. It is also possible that the charge level light will illuminate when the
control system is dispensing LCO2.
Placing LCO2 control system in storage
CAUTION Any rise in temperature will cause a rapid rise of pressure of
liquid CO2 trapped in the supply line. After turning off the LCO2 supply,
bleed the supply line by lowering the LCO2 setpoint sufficiently to cause
the LCO2 solenoid to open. With the solenoid open, disconnect the supply
line from the backup system control unit.
After disconnecting the LCO2 supply line, set the LCO2 control to +50 oC
and plug the unit into the power supply. This will keep the battery charged
and prevent the solenoid from operating.
LIQUID CO2BACKUP REFRIGERATION
This accessory, when connected to a user supplied siphon tank of liquid
CO2, will provide a source of backup refrigeration in case of power failure to
the mechanical refrigeration equipment. The control assembly for this
accessory operates over a range of 200VAC to 240VAC, 10, either 50Hz or
60Hz. There is a continuous charging battery backup power supply for
operation of the accessory during power failure.
Installation:
1. Place the LCO2 control system on top of the System B mechanical
section.

SECTION 100 – PRODUCT INTRODUCTION
6Generic MBF700 Service Manual Thermo Fisher Scientific
2. Place the CO2control system on top of the freezer lid.
3. Locate the switch hole in the left hand side of the right hand
machine compartment cover and remove the cover plate that was
factory installed.
4. Remove the machine compartment cover by locating and removing
the screws at the back and at front securing the cover to the housing.
5. Locate the lid switch in the accessory kit.
6. Locate the leads from the control unit with two-prong connector.
Feed the leads through the hole provided in the back of the unit,
route through machinery compartment to the left front and up
through the second hole provided. Then feed the leads through the
switch hole provided in the machinery compartment cover and
connect to the switch terminals. Snap the switch into the hole
making sure that the curved side of the plunger is on the bottom
side.
7. Replace the machinery compartment cover securing with the screws
front and back.
8. Identify the CO2discharge and control assembly mounted in the
perforated housing.
9. Remove the coiled control bulb and the CO2discharge tube from
the housing, insert the bulb through the rear cabinet porthole and
reassemble the bulb to the housing inside the cabinet. Mount the
housing to the right inside wall of the cabinet using two of the three
factory installed screws. Route the CO2discharge tube through the
porthole and, after loosening the screws securing the rear breaker
strip, slide the discharge tube under the retainer strip and re-tighten
the screws.
10. The assembly of the CO2to the cabinet is now complete.