Carnes EK Installation Manual

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Installation and Maintenance Manual IM 902

McQuay Direct Expansion (DX) Cooling Coils

Types EN, EF, ER, EJ, EK

Group: Applied Air

Part Number: IM 902

Date: February 2008

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Contents

Introduction .............................................................. 3

General Information................................................ 3

Hazard Identification Information............................ 3

Receiving Instructions ............................................ 3

Coil Types............................................................... 3

Model EN............................................................ 3

Model EF ............................................................ 3

Model ER............................................................ 3

Model EJ............................................................. 3

Model EK ............................................................ 3

Nomenclature......................................................... 4

Installation ................................................................ 5

Mounting ................................................................ 5

Installation.............................................................. 5

Operation and Maintenance.................................... 7

Operation ............................................................... 7

General .............................................................. 7

Maintenance .......................................................... 7

General .............................................................. 7

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Introduction

General Information

Guidelines for the installation, operation and maintenance of McQuay direct expansion (DX) cooling coils have been provided to help insure proper performance of the coils and their longevity. These are general guidelines that may have to be tailored to meet the specific requirements of any one job. As always, an experienced installation company or fully trained individual should perform the installation and maintenance of any coil. Protective equipment such as safety glasses, steel toe boots and gloves are recommended during the installation and routine maintenance of the coil.

Hazard Identification Information

DANGER

Dangers indicate a hazardous situation which will result in death or serious injury if not avoided.

WARNING

Warnings indicate potentially hazardous situations, which can result in property damage, severe personal injury, or death if not avoided.

3 Damaged and/or missing items should be noted on the

carrier's freight bill and signed by the driver.

4 For additional assistance, contact your local McQuay sales

representative.

Coil Types

Model EN

This evaporator coil is used for applications where capacity control is not required. Single or multiple distributors are available depending on the number of circuits required. Model EN (Figure 1) evaporators utilize dual suction connections when multiple distributors are used.

Model EF

Face control (model EF - Figure 1) is another evaporator coil option offered. Face control is the simplest form of capacity control. These coils are normally furnished with two distributors and two suction connections offering 50% capacity reduction capabilities.

Model ER

CAUTION

Cautions indicate potentially hazardous situations, which can result in personal injury or equipment damage if not avoided.

Receiving Instructions

1 All McQuay coils are factory tested at 315 psig minimum

air pressure while submersed in water, inspected, and carefully packaged.

2 Damage to the coils can occur after they have left the

factory. Therefore, the coils should be inspected for shipping damage upon receipt. The freight bill should also be checked against items received for complete delivery.

Figure 1: Evaporator Coil Types

McQuay offers a row control option (model ER - Figure 1) for six row evaporator coils. These coils are split into two rows and four rows that offer approximately a 50% capacity reduction.

Model EJ

These evaporator coils (model EJ - Figure 1) come with interlaced circuiting. This form of capacity control utilizes two distributors with each feeding every other tube in the first row of the coil. Each distributor has a separate suction connection.

Model EK

For applications that require face control and interlaced circuits, we offer evaporator model EK (Figure 1). Interlaced face control utilizes four distributors and four suction connections.

Normal

Rows 2, 3, 4, 5

6, 8, 10, 12

McQuay IM 902 3

Face Control

Rows 2, 3, 4, 5

6, 8, 10, 12

Row Control

Rows 6

2 Distributors

Interlaced Rows 3, 4, 6, 8 2 Distributors

Interlaced

Face Control

Rows 4, 8

4 Distributors

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Introduction

Nomenclature

5 E N 14 06 C 24.00 144.00x

Tube O.D.

3=3/8" 4=1/2" 5=5/8"

Coil Type

E = Evaporator

Circuiting

N = Normal F = Face Control R = Row Control J = Interlaced K = Interlaced Face Control

Finned Length (inches)

Finned Height (inches)

Fin Design

A - flat (AI, Cu) B - corrugated (AI, Cu) C - sine wave (AI, Cu) F - flat (SS, CS)

Rows Deep

Fins Per Inch

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Installation

Mounting

Position the coil such that the suction header is at the entering airside of the coil and the distributor tubes are at the leaving airside of the coil. This orientation provides counter flow heat exchange that is required for proper coil performance.

The suction connection is located at the bottom of the coil when properly installed (see Figure 1 on page 3).

Installation

CAUTION

Sharp edges on sheet metal and fasteners can cause personal injury. This equipment must be installed, operated,

and serviced only by an experienced installation company and fully trained personnel. Protective equipment such as safety glasses, steel toe boots and gloves are recommended during the installation and routine maintenance of the coil.

CAUTION

Failure to properly install the coil can result in irreparable damage to the coil as well as other components in the system.

(Figure 2). If a hot gas bypass kit was ordered with the coil, the nozzle that is in the distributor will need to be relocated into the hot gas bypass assembly (Figure 3).

4 All field brazing and welding should be performed using

high quality materials and an inert gas purge (such as nitrogen) to reduce oxidation of the internal surface of the coil.

Figure 2: Distributor

Retainer Ring

Figure 3: Hot Gas Bypass Kit

Nozzle

Distributor

If you are unsure about any portion of the installation, contact your local steam specialist for assistance.

1 Carefully remove the coil from the shipping package to

avoid damage to the finned area. Damaged fins can be straightened using an appropriate fin comb.

2 Proper clearance should be maintained between the coil

and other structures such as the fan, filter racks, transition areas, etc.

3 Inspect the refrigerant distributor and verify that the nozzle

is in place. The nozzle is generally held in place by a retaining ring or it is an integral part of the distributor itself

Figure 4: Hot Gas Bypass Kit Installed

Suction Header

Distributor

Equalizer Line

Liquid Line

Expansion Valve

Hot Gas By-Pass

Hot Gas Side Port

Nozzle

5 If a hot gas bypass kit was ordered with the coil, install it

now (refer to Figure 4 for a general installation diagram). Complete installation instructions are in the box that contains the hot gas bypass kit. Align the side port with the hot gas line prior to brazing into place (Figure 4).

Coil

Suction Line

Remote Sensing Bulb

McQuay IM 902 5

Straps Suction Connection

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Installation

6 Connect the suction line and suction connection (Figure 4

on page 5).

7 Install the expansion valve (Figure 4 on page 5). Follow the

expansion valve manufacturer’s recommendations for installation to avoid damaging the valve. If the valve is externally equalized, use a tubing cutter to cut off the plugged end of the factory installed equalizer line. Next, use a de-burring tool to remove any loose metal from the equalizer line (Figure 4 on page 5) and attach it to the expansion valve. If the valve is internally equalized, the factory installed equalizer line can be left as is or it can be cut back and sealed.

8 The expansion valve’s remote sensing bulb (Figure 4 on

page 5) should be securely strapped to the horizontal run of the suction line at the 3 or 9 o’clock position and insulated.

9 Connect the liquid line (Figure 4 on page 5) to the

expansion valve. Pressurize the coil, expansion valve assembly and suction connection to 100 psig with dry nitrogen or other suitable gas. The coil should be left pressurized for a minimum of 10 minutes.

10 If the coil holds pressure, the hook-up can be considered

leak free. If the pressure drops by 5 psi or less, repressurize the coil and wait another 10 minutes. If the pressure drops again, there are more than likely one or more small leaks, which should be located and repaired. Pressure losses greater than 5 psi would indicate a larger leak, which should be isolated and repaired. Be sure to

check valves and fittings as potential sites for leakage or bleed. If the coil is found to be leaking, contact your local McQuay coil representative.

Note: Unauthorized repair of the coil may void the coil’s

warranty (see the McQuay warranty policy on back cover).

11 Use a vacuum pump to evacuate the coil and any

interconnecting piping that has been open to atmosphere. Measure the vacuum in the piping using a micron gauge located as far from the pump as possible (the vacuum at the pump will be greater than the rest of the system). Evacuate the coil to 500 microns or less then close the valve between the pump and the system. If the vacuum holds to 500 microns or less for one minute, the system is ready to be charged or refrigerant pumped down in another portion of the system can be opened to the coil. A steady rise in microns would indicate that moisture is still present and that the coil should be further vacuumed until the moisture has been removed.

12 Failure to obtain a high vacuum is indicative of a great deal

of moisture or a small leak. Break the vacuum with a charge of dry nitrogen or other suitable gas and recheck for leaks (soapy water works well). If no leaks are found, continue vacuuming the coil until the desired vacuum is reached.

13 All field piping must be self-supporting.

6 McQuay IM 902

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Operation and Maintenance

Operation

General

1 Proper air distribution is vital to coil performance. Airflow

anywhere on the coil face should not vary by more than 20%.

2 The drain pan and associated piping (drain line and trap)

should be installed so that there is no standing water in the drain pan and that no blow-through occurs.

3 Air velocities should be maintained between 200-550 feet

per minute.

Maintenance

DANGER

Follow the manufacturer’s guidelines for lockout/tagout and disconnect all power to the unit before performing maintenance. Contact with high voltage power will cause electrical shock, resulting in severe personal injury or death.

WARNING

Moving parts, high pressure, and/or high temperature fluids can cause serious personal injury.

General

1 Filters should be inspected on a regular basis and changed

as needed. Maintaining clean filters is a cost effective way to help maintain maximum coil performance and service life.

2 Periodic inspection of the coil for signs of corrosion and/or

leaks is recommended. Repair and replacement of the coil and the connecting piping, valves, etc., should be performed as needed by a qualified individual(s).

3 Should the coil surface need cleaning, caution should be

exercised in selecting the cleaning solution as well as the cleaning equipment. Improper selection can result in damage to the coil and/or health hazards.

4 Suggested cleaning instructions:

a When handling strong chemicals, be sure to wear

chemical impervious gloves, apron, and splash goggles.

b Acti-Brite (AB-1) is the recommended cleaning

solution. Contact your local McQuay Parts Distributor.

c Determine required dilution for the specific application.

It is recommended to start with a dilution ratio of 10:1 and increase concentration until the desired results are achieved.

d As with mixing all acids, place the desired amount of

water into the tank and then add the chemicals.

e Turn off fans and allow hot coils to cool before

applying.

f Using plain water, wet both the coil as well as the area

surrounding the equipment. Wetting the coil with water aids in product penetration and performance.

g Apply properly diluted product to coil surface.

Whenever possible, apply solution from the outlet side of the coil. Allow solution to remain on surface, normally 5-10 minutes. Do not allow solution to dry on

the coil.

CAUTION

Carefully read and follow the manufacturer's recommendations before using any cleaning fluid.

Note: In extreme cases, application may have to be

repeated to achieve desired results.

h If foaming does not occur, check for extreme grease

buildup which will slow cleaning process. Foaming may not occur if coil is coated or painted.

i Rinse coils, tools, and surrounding area thoroughly after

the coil cleaning.

5 Clean the coil from the leaving airside so that foreign

material will be washed out of the coil rather than pushed further in.

6 Periodic inspection of the coil for signs of corrosion and for

leaks is recommended. Small leaks can be detected using a Halide torch. Repair and replacement of the coil and the connecting piping, valves, etc., should be performed as needed by a qualified individual.

7 The use of filter-dryers in the system piping is

recommended along with a sight glass that has a moisture indicator. Replace the filter dryer(s) as needed.

Note: Refrigerant conversions are beyond the scope of this

manual and should only be performed by qualified parties.

McQuay IM 902 7

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McQuay Training and Development

Now that you have made an investment in modern, efficient McQuay equipment, its care should be a high priority. For training information on all McQuay HVAC products, please visit us at www.mcquay.com and click on training, or call 540-248-9646 and ask for the Training Department.

Warranty

All McQuay equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product Warranty. Consult your local McQuay Representative for warranty details. Refer to Form 933-43285Y. To find your local McQuay Representative, go to www.mcquay.com.

This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.mcquay.com.