Gentek 3950201 User Manual

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Chapter 2: Prerequisites

Support, Vibration and Movement Requirements

At a minimum, the supporting structure usually consists of a base cabinet and chemical-resistantwork surface.

The ability for analytical balances to accommodate vibration varies with type and brand. More advanced balances have improved tolerance, however in the preparation of a balance enclosure site, please consider the following:

Avoid tubular stands or mobile benches that have the potential of moving when touched.

Work surfaces should be of a thick rigid material that remains stable when buttons are pressed. An epoxy benchtop or accessory work surface is a minimum requirement.

A bench that is rigidly mounted to the floor or fixed to the wall, but not both, may be appropriate.

The corners of a building typically have less vibration than the center.

The bench with the balance enclosure should not contain any vibration-producingequipment, such as shakers or pumps.

Marble, granite or epoxy balance tables are generally recommended by the manufacturers of analytical and microbalances. (See the installation instructions in Chapter 3).

Marble slabs with dampening pads placed within the enclosure are also an effective low cost means of controlling vibration.

Temperature Variation Requirements

The extent the balance readings are influenced by temperature variations is a function of the balance design. Most manufacturers would suggest that a temperature drift of 1-2°Cis generally tolerable. Only validation through your Operational Qualification protocol can define what is acceptable. To minimize the potential for temperature variations:

Never install balances near heating sources such as radiators and hot plates.

Do not place the balance and enclosure on a bench that would receive direct sunlight.

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Chapter 2: Prerequisites

Humidity and Static Electricity Requirements

Electrostatics can be troublesome in a balance enclosure. It is important to understand and, to the extent possible, control static charges. An electrostatic charged vessel, sample or enclosure can apply forces and lead to errors in weighing. The repulsion or attraction can be detected with micro, semi micro and analytical balances. Static charges can also lead to particulates being attracted to surfaces within the balance enclosure. Containment of harmful powders, prevention of cross-contaminationand clean up are enhanced when static attraction of powders is minimized. The construction of the XPert Filtered Balance System and XPert Filtered Balance Station avoid the use of plastics, which are highly insulative. The advantages to the glass andepoxy-coatedmetal construction are twofold:

1.The enclosure does not contribute high electrostatic forces affecting the precision of the balance.

2.The attraction and ultimate accumulation of powders, (hazardous or nuisance), are minimized on the inside of the enclosure.

To correct or ensure against electrostatic issues, the following additional measures may be prescribed to improve weighing operations.

Maintain a humidity level between 45 and 60%. The ability to sustain this humidity range can be challenging depending upon the regional climate and HVAC system.

Ionizers in various forms (guns, bars and blowers) are effective ways to flood an area with ions and essentially “neutralize” electrostatic electricity.

Background on Electrostatics or Static Electricity

Electrostatic charges on a surface such as the wall of a balance enclosure are not created by moving air. Gases do not cause the charge. Impurities within the air impinging upon surfaces dictate the polarity and magnitude of the charge. The process, triboelectrification, occurs when the dust particles contact the surface, creating friction and electrons move across the interface.

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Chapter 2: Prerequisites

The ability of a material to become polarized is a property known as permittivity. On highly insulative materials like acrylic, ions or charged molecules are strongly bound to the surface by polarization forces. The higher the force, the higher is the permittivity value of the material. It is suggested by balance manufacturers that the use of high permittivity materials, such as plastic be avoided.

Since static electricity is a surface phenomenon, materials can also be classified by their surface resistivity measured in ohms per square. The table below lists the surface resistivity of various classes of material.

Surface Resistivity Table

Material

Surface Resistivity

Example

Conductive

0

 

105 per square

Skin, Metals

Static dissipative

105

109

per square

Glass

Antistatic

109

1012

per square

Polyethylene bag

Insulative

1012 per square

Acrylic, Packing foam, Styrofoam

Location and Air Current Requirements

The XPert Filtered Enclosures have been designed to contain hazards by negating typical cross drafts and turbulence within the opening. Air movement does not affect most modern balances with draft shields. However, as a precautionary safety measure and a higher level of quality management, it is recommended that the enclosure be placed in an area to avoid:

High traffic areas where walking might cause an air disturbance or be a nuisance to balance readings.

Overhead or wall HVAC diffusers, fans, radiators or other lab equipment producing air currents.

Next to doorways or windows that may be opened.

Exhaust and Blower

Requirements

XPert

System

The XPert Filtered Balance System uses an integral motorized impeller to draw room air past the operator and through the enclosure. This contaminated air is then pushed through the HEPA filter. The HEPA-filteredexhaust air is then forced out the top of the enclosure. An optional carbon filter may be installed on the downstream side of the HEPA filter to protect against nuisance odors.

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Chapter 2: Prerequisites

The HEPA-filteredexhaust air can be recirculated into the laboratory or exhausted outside with the addition of the exhaust connection kit and remote blower listed in Chapter 7.

The XPert Filtered Balance Station does not include the motorized impeller and must be exhausted to the outside by a remote blower. The XPert Filtered Balance Station remote blower may be switched from the blower switch on the enclosure. See electrical Requirements in Chapter 2, and Electrical Supply Connections in Chapter 3. Only one 6" exhaust connection is required for the 2', 3', or 4' XPert Filtered Balance Stations to exhaust to the outside.

Data for the exhaust volume, noise pressure and enclosure static pressure loss are listed for each filtered enclosure model at face velocities of 60, 75, 80, 90, 100, and 105 fpm.

XPert

Station

 

 

 

 

XPert

 

Xpert

 

 

 

 

 

Station

 

System

Xpert

 

 

 

 

Initial Static

XPert

Max.

System

 

 

 

 

Pressure

System

Equivalent

Max.

 

 

Face

Exhaust

Loss with

Noise

Resistance

External

Enclosure

 

Velocity

Volume

HEPA filter

Pressure

of 6" Duct

Static

Width

Model Description

(fpm)

(CFM)

(in w.g.)

db(A)

(Ft)

Pressure

2'

2' XPert Filtered Balance System

60

85

.35"- .41"

48-53

400

.20"

 

2' XPert Filtered Balance Station

75

110

.45" - .54"

49-55

220

.19"

 

 

80

115

.48" - .57"

50-56

200

.18"

 

 

90

130

.56" - .65"

51-57

140

.16"

 

 

100

145

.62" - .72"

53-58

80

.13"

 

 

105

155

.65" - .76"

54-59

70

.12"

3'

3' XPert Filtered Balance System

60

130

.37" - .43"

48-53

130

.15"

 

3' XPert Filtered Balance Station

75

165

.50" - .58"

52-56

65

.12"

 

 

80

175

.53" - .62"

53-57

50

.11"

 

 

90

200

.61" - .71"

55-58

35

.09"

 

 

100

220

.68" - .79"

58-61

25

.08"

 

 

105

230

.71" - .88"

60-64

20

.07"

4'

4' XPert Filtered Balance System

60

175

.40" - .46"

49-54

100

.20"

 

4' XPert Filtered Balance Station

75

220

.53" - .62"

54-58

60

.19"

 

 

80

235

.57" - .66"

58-61

50

.18"

 

 

90

265

.68" - .78"

60-63

35

.16"

 

 

100

295

.76" - .87"

62-66

25

.13"

 

 

105

310

.80" - .91"

64-67

20

.12"

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Chapter 2: Prerequisites

Proper blower selection can be determined from these exhaust requirements and the total system static pressure loss. For outside exhaust, the enclosure must be connected to either a dedicated blower or a house exhaust system.

Labconco offers accessory remote blowers listed in Chapter 7.

Contact Labconco for blower sizing assistance.

If the enclosure is connected directly to a house exhaust system, an

!adjustable damper (or valve) must be installed to control the airflow properly. This is equally important when a house exhaust system is controlling multiple filtered enclosures. See Chapter 7 for accessory adjustable damper ordering information.

XPert

Station

Electrical Requirements

Standard duplex electrical receptacles should be nearby for connecting the filtered enclosure, or other equipment, such as a balance for weighing operations. The enclosures include iris passthroughs to allow electrical cords through the back of the enclosure without leaving a large hole for contaminants to escape.

The remote blower for the XPert Filtered Balance Station may be connected to the blower switch on the enclosure. The blower switch is connected to a relay whose wires are terminated in the junction box behind the front panel. We recommend a maximum amperage of 6 amps for this circuit to the remote blower. Please refer to the wiring diagrams in Appendix C. Connect the blower wires inside the junction box to the remote blower per local electrical codes.

Space Requirements

The dimensions for the different models are shown in Appendix B:

Dimensions.

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CHAPTER3

GETTINGSTARTED

Now that the site for your filtered enclosure is properly prepared, you are ready to unpack, inspect, install, and validate your system. Read this chapter to learn how to:

Unpack and move the enclosure.

Set up the enclosure with the proper supporting structure and work surface.

Connect to an exhaust system if applicable.

Installation of HEPA and accessory Odor Control carbon filters.

Connect the electrical supply.

Set the face velocity with the speed control adjustment.

Arrange validation for the enclosure.

Seal the enclosure to the work surface.

Depending upon which model you are installing, you may need common mechanical and electrical installation tools in addition to 5/16", 3/8", 7/16", and 1/2" wrenches, ratchets, sockets, a nut driver set, a flat-bladescrewdriver, a Phillips screwdriver, and a carpenter level to complete the instructions in the chapter.

Each enclosure model weighs between 125 to 195

!lbs. each (55 to 85 kg). The shipping container allows for lifting with a mechanical lift truck or floor jack. If you must lift the enclosure manually, follow safe-liftingguidelines.Do not

lift by the front air foil.

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Chapter 3: Getting Started

The United States Interstate Commerce Commission rules require that claims be filed with the delivery carrier within fifteen (15) days of delivery.

Unpacking the Enclosure

Carefully remove the shrink-wrapor carton on the enclosure and inspect it for damage that may have occurred in transit. If damaged, notify the delivery carrier immediately and retain the entire shipment intact for inspection by the carrier.

DO NOT RETURN GOODS WITHOUT THEPRIOR AUTHORIZATION OF LABCONCO.

UNAUTHORIZED RETURNS WILL NOT BE ACCEPTED.

IF ENCLOSURE WAS DAMAGED IN TRANSIT,YOU MUST FILE A CLAIM DIRECTLY WITH

THE FREIGHT CARRIER. LABCONCO CORPORATION AND ITS DEALERS ARE NOT RESPONSIBLE FOR SHIPPING DAMAGES.

Do not discard the packing material until you have checked all of the components and tested the enclosure.

We recommend that you do not remove the enclosure from its shipping container until it is ready to be placed into its final location. Move the unit by placing a flat, low dolly under the shipping skid, or by using a floor jack.

!Do not move the enclosure by tilting it onto a hand truck.

Installing the Filtered Enclosure on a Supporting Structure and Work Surface

Use caution when lifting or moving the enclosure.

When installing the enclosure onto a chemical-resistantwork surface or benchtop, ensure that the structure can safely support the combined weight of the enclosure and any related equipment. The work surface should be at least as wide as the enclosure to properly support it. The front of the enclosure should be aligned within

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Chapter 3: Getting Started

0.36" of the front of the work surface. Mounting holes are provided in the Labconco accessory work surfaces to secure the enclosure.

Work Surface Specifications

The work surface should be smooth, rigid, and durable, such as a chemical-resistantepoxy resin. The surface should benon-porousand resistant to the powders, solvents and chemicals used in conjunction with the XPert Filtered Enclosure. The work surface should also contain a dished recessed area for containing primary spills.

Work Surface and HEPA Filtered Enclosure Installation

1.Level the base cabinets and the work surface. Work surface should be placed flush with the front of the base cabinet as shown in Figure 3-1.

2.Position the work surface in its intended location and with the front of the work surface towards you. (Rear mounting holes are located close to the rear edge.)

3.Secure the work surface to the base cabinet with a structural adhesive or silicone sealant.

4.Insert the supplied mounting screws in the four holes. Allow a minimum of 1/8" clearance under the head of the screw for positioning the enclosure.

5.Place the enclosure on the work surface and slide the rear flange and front air foil flanges under the mounting screw heads.

6.Tighten the four screws to complete the installation.

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Chapter 3: Getting Started

Figure 3-1

Filtered Enclosure Installation

14

XPert

Station

!

!

Chapter 3: Getting Started

Connecting to the Exhaust System (Optional on XPert Filtered Balance System)

WARNING: The weight of the exhaust ductwork system must be supported independently of the enclosure superstructure or damage may occur.

The exhaust system should be installed by a qualified HVAC contractor.

The exhaust connection on the XPert Filtered Balance Station has been designed to accept 6" diameter ductwork as shown in Figure 3-2.The exhaust connection ships uninstalled on the top and needs to be fastened with the screws provided. See Chapter 7 for ordering exhaust transition kits for the XPert Filtered Balance System. Exhaust transition kits aid in the removal of chemicals or applications where a higher degree of powder and particulate removal is required. Review Chapter 2 for exhaust prerequisites and review Chapter 7 for ordering blower exhaust equipment. See Figure3-2for the XPert Station and Figure3-3for exhaust kit options for the XPert Filtered Balance System.

Consult Labconco Customer Service should you require help sizing your blower for the exhaust volume and system static pressure loss.

To ensure compatibility, the selected exhaust duct material should match the enclosure, procedures and chemical applications.

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