CMT MANUAL - Netafim · CMT Manual offers guidelines the general installation of CMT and in directly related equipment. It is not comprehensive but covers aspects that in the experience

CMT MANUAL 1.5 GENERAL INSTALLATION

Version 1.00 JA20120201 General Installation Page 1

TABLE OF CONTENTS

INDEMNITY ............................................................................................................................................ 3

DOCUMENT INFORMATION .................................................................................................................... 3

ACKNOWLEDGEMENTS .......................................................................................................................... 3

1.5.1. CONSTRUCTION AND CIVIL WORK ................................................................................................. 4

1.5.1.1 CONSTRUCTION AND CIVIL WORK - GENERAL ............................................................................... 4

1.5.1.1.1 FOUNDATIONS ............................................................................................................................ 4

1.5.1.1.2 FOUNDATION WALLS .................................................................................................................. 5

1.5.1.1.3 CONCRETE FLOORS – INCLUDING SLABS ON THE GROUND ....................................................... 5

1.5.1.2 CONSTRUCTION AND CIVIL WORK – ACCESSIBILTY ....................................................................... 5

1.5.1.3 CONSTRUCTION AND CIVIL WORK – DRAINAGE ............................................................................ 8

1.5.2. TANKS ........................................................................................................................................ 11

1.5.2.1 TANKS – IRRIGATION STORAGE ................................................................................................... 11

1.5.2.1 TANKS – FERTILISER STORAGE ..................................................................................................... 12

1.5.3. PIPING, PUMPS AND EQUIPMENT ............................................................................................... 12

1.5.3.1 PIPING .......................................................................................................................................... 12

1.5.3.1.1 uPVC PIPING .............................................................................................................................. 12

1.5.3.2 PUMPS AND EQUIPMENT ............................................................................................................ 15

1.5.3.3 ELEVATED MOUNTING OF PIPING, PUMPS AND EQUIPMENT .................................................... 15

1.5.3.4 EMERGENCY FERTILISER INJECTION............................................................................................. 17

1.5.4. ELECTRICAL................................................................................................................................. 18

1.5.4.3 CONTROL PANEL .......................................................................................................................... 18

1.5.4.3.1 CONTROL PANEL - IRRIGATION ................................................................................................. 18

1.5.4.4 GENERAL WIRING ......................................................................................................................... 20


LIST OF FIGURES

FIGURE 1. A CLUTTERED HEAD CONTROL WITH ALL EQUIPMENT AND PIPING MOUNTED ON TOP OF THE FLOOR ............................................................................................................................................ 6

FIGURE 2. A HEAD CONTROL WITH ESSENTIAL EQUIPMENT ON THE FLOOR AND PIPING BELOW FLOOR LEVEL .............................................................................................................................................. 6

FIGURE 3. CONCRETE TRENCH – CONSTRUCTION OF TRENCH WALLS IN BRICK ....................................... 7

FIGURE 4. CONCRETE TRENCH – COVERED WITH STEEL GRID ................................................................... 7

FIGURE 5. HEAD CONTROL LAYOUT – FURNISHED ABOVE AND SHOWING DOWN SLOPE ARROWS UNDERNEATH ............................................................................................................................. 8

FIGURE 6. PUMP, PIPING AND ELECTRIC TRUNKING ELEVATED ABOVE HEAD CONTROL FLOOR ............. 9

FIGURE 7. A LEVEL HEAD CONTROL FLOOR WITH INADEQUATE DRAINAGE ........................................... 10

FIGURE 8. PARTIALLY SUBMERGED ELECTRIC CABLE TRUNKING ............................................................ 10

FIGURE 9. BULK STORAGE TANK FOR IRRIGATION WATER ...................................................................... 11

FIGURE 10. ONE-WAY-OUT AIR VALVE FITTED TO A SUCTION PIPE ........................................................ 11

FIGURE 11. FERTILISER STORAGE TANKS ON A WALLED ‘ISLAND’ ........................................................... 12

FIGURE 12. PVC PIPING FASTENED TO THE WALL OF A CONCRETE TRENCH .......................................... 13

FIGURE 13. PVC PIPING ENCASED IN CONCRETE ..................................................................................... 13

FIGURE 14. CONCRETE TRENCH - SPACE STEEL PROFILES 1m APART ...................................................... 14

FIGURE 15. CONCRETE TRENCH - RAISE THE STEEL PROFILES ABOVE THE FLOOR ON STAINLESS STEEL THREADED ROD ............................................................................................................................. 14

FIGURE 16. CONCRETE TRENCH – COVERED WITH STEEL GRID ............................................................... 15

FIGURE 17. GALVANISED STEEL STRUT – 20 MM X 40 MM ..................................................................... 16

FIGURE 18. GALVANISED STEEL SLOTTED STRUT – 40 MM X 40 MM WITH 14 MM WIDE SLOTS .......... 16

FIGURE 19. A VENTURI BRIDGE AS A FERTILISER INJECTION BACK-UP .................................................... 17

FIGURE 20. EXAMPLE OF AN ELECTRIC CONTROL PANEL FOR A HEAD CONTROL ................................... 19

FIGURE 21. EXAMPLE OF A PUMP WITH ITS OWN ISOLATION SWITCH IN CLOSE PROXIMITY ............... 19


INDEMNITY Netafim South Africa (Pty) Ltd has taken all reasonable care in ensuring the integrity and reliability of the information contained in this document. Despite this Netafim South Africa (Pty) Ltd. takes no responsibility for any damage or loss that may result from the use of this manual. This document should be regarded as the property of Netafim South Africa (Pty) Ltd. This document is not intended for further training and neither may it be reproduced nor copied in its current form or temporary form. This document may not be revealed and/or carried over to any third party without the explicit written consent of Netafim South Africa (Pty) Ltd. This document is presented with the exclusive aim of notifying selected potential clients regarding General Installation. Receipt or the possession of this document does not imply rights and the contents should be viewed as a proposal only. This document is neither issued as a guarantee, nor does it confirm any legal obligations on Netafim South Africa (Pty) Ltd whatsoever. Netafim South Africa (Pty) Ltd reserves the right to make changes in its products and in the General Installation without prior notice. DOCUMENT INFORMATION Version: 1.00 Last updated: 01 Feb 2012 ACKNOWLEDGEMENTS Netafim South Africa Electroparts (Pty) Ltd, Cape Town O-Line Support Systems Cape Town (Pty) Ltd


This section of the CMT Manual offers guidelines in the general installation of CMT and directly related equipment. It is not comprehensive but covers aspects that in the experience of Netafim, tend to be overlooked. The CMT technician’s involvement in general installation is mostly with irrigation installations and most of this is in the head control. The CMT technician’s involvement in general installation with climate control is more limited. This section of the CMT Manual deals mainly with irrigation. Where general installation does concern climate control, it is handled as a separate section underneath the irrigation.

1.5.1. CONSTRUCTION AND CIVIL WORK The head control should be designed and constructed in a way that facilitates and ensures:

• Safety. Mechanical and electrical. • Accessibility. Ease of movement and access to all equipment. • Drainage. Head controls are naturally wet and subject to spillage of water and other liquids.

It is imperative that this spillage is drained away. 1.5.1.1 CONSTRUCTION AND CIVIL WORK - GENERAL General guidelines with minimum requirements are given below for single story buildings with a floor area less than 200 m².

• Foundations • Foundation walls • Concrete floors and slabs

A local engineer should be consulted for soil and load conditions. 1.5.1.1.1 FOUNDATIONS General. The top of all foundations must be at least 300 mm below natural ground level (NGL). Where the foundation is stepped to accommodate the slope of natural ground level, it must have a 500 mm overlap with steel reinforcing (rebar). Steel reinforcing should comprise two x Y12 deformed rebars side-by-side, running the length of the foundation. These rebars should have a minimum of 100 mm cover above and 100 mm below with 50 mm clearance from each side of the foundation. R6 round cross bars installed every 1 000 mm (pitch) to bind the Y12 rebars, may be added for clay or problem soils. Foundations for non-load bearing walls. A minimum foundation 600 mm wide and 200 mm deep cast in 15 mPa concrete to support a 230 mm (double brick) foundation wall in the centre of the foundation. Foundations for single-story load bearing walls and containers*. A minimum foundation 650 mm wide and 250 mm deep cast in 15 mPa concrete to support a 230 mm (double brick) foundation wall in the centre of the foundation.

NB


*In the case of a container used as a head control with normal irrigation equipment installed inside, the foundations are cast on which to mount the container along its two long sides only to ensure proper ventilation below the container. Foundations for double-story load bearing walls and fertiliser tank islands. 750 mm wide and 300 mm deep cast in 15 mPa concrete to support a 230 mm (double brick) or 340 mm (three brick) foundation wall along the centre of the foundation. 1.5.1.1.2 FOUNDATION WALLS Use standard clay bricks or cement bricks (minimum 7 mPa strength). Install brick force (2.8 – 3.5mm ladder type) on every second layer. If concrete blocks are used, they must be 190 mm wide, filled with 15 mPa concrete and mechanically vibrated to ensure proper filling of all cavities. Foundation walls must be less than 1.5 m high from the top of the foundation to the top of the concrete floor. See the fill limitation under Concrete Floors that follows. 1.5.1.1.3 CONCRETE FLOORS – INCLUDING SLABS ON THE GROUND Fill. All floors and slabs must be at least 200 mm above natural ground level. Install a 250 micron (0.25 mm) Polyolefin under-floor membrane (DPC plastic) between the final fill compaction layer and the concrete. Filling must be of good material and of the correct moisture content. The fill must be placed in layers with maximum depth of 100 mm per layer for hand compaction and 150 mm per layer if mechanically compacted. It is recommended that soil compaction tests be done to ensure proper compaction. The maximum depth of fill under concrete slabs is 1 m. Concrete floors. These should be cast in 25 mPa concrete. Lay Ref. 245 reinforcing mesh with 6.3 mm diameter wire in squares with a 200 mm pitch, through the middle of the floor’s depth. Floor thickness:

• No traffic* : 100mm • Light traffic : 150mm

*Ref. 245 reinforcing mesh is optional. Concrete slabs for fertiliser tank islands. Cast in 30 mPa concrete: Lay Ref. 245 reinforcing mesh with 6.3 mm diameter wire in squares with a 200 mm pitch, through the middle of the slab’s depth. The slab thickness is 150 mm. The maximum height is 900 mm above ground / floor level. Multi-story buildings are not applicable for standard head controls. Contact a qualified civil engineer to design and specify. 1.5.1.2 CONSTRUCTION AND CIVIL WORK – ACCESSIBILTY Equipment to which access is required can be mounted on the floor with sufficient working space made around each item of equipment for ease of access. The rest can be below the floor. Most piping within a head control need not be accessed on a regular basis. It can be placed out of the way and fixed below the working area in a concrete trench that is covered over by a steel grid.


Fixing all piping at floor level limits necessary operational and service access to equipment such as dosing units as shown in FIGURE 1. This is cluttered and difficult to work in. By contrast, placing piping below the general floor level, as well as thoughtful positioning of equipment such as in FIGURE 2, facilitates easy access to that equipment.

FIGURE 1. A CLUTTERED HEAD CONTROL WITH ALL EQUIPMENT AND PIPING MOUNTED ON TOP OF THE FLOOR

FIGURE 2. A HEAD CONTROL WITH ESSENTIAL EQUIPMENT ON THE FLOOR AND PIPING BELOW FLOOR LEVEL

Concrete trenches should have the following dimensions: Depth – 400 mm Width – 600 mm or 1 200 mm according to the piping and equipment to be contained. Slope – 1:200 or steeper, downwards towards the drainage exit from the building.


FIGURE 3. CONCRETE TRENCH – CONSTRUCTION OF TRENCH WALLS IN BRICK Trench walls may be in concrete blocks instead of brick but the cavities should then be concrete-filled if grouting into the trench wall is necessary. See FIGURE 12.

FIGURE 4. CONCRETE TRENCH – COVERED WITH STEEL GRID


1.5.1.3 CONSTRUCTION AND CIVIL WORK – DRAINAGE The topography on which the head control is built should indicate where to place the exit point to which all inside drainage should leave the building. All floors and concrete trenches should drain to this drain outlet point. It is neither necessary nor desirable to lay a level floor in a head control. A 1:200 slope will allow drainage of any spillage. The floor’s slope should drain into the concrete trenches, which in turn should be sloped to the exit point mentioned above.

FIGURE 5. HEAD CONTROL LAYOUT – FURNISHED ABOVE AND SHOWING DOWN SLOPE ARROWS

UNDERNEATH

Slo

peS

lope

Slope

Slope Slope

Slope

Slope

Slope

Drain outlet

Head control floor

Trench

Trench

Fertiliser tank island


All equipment should be elevated above the levels of the floor and the concrete trenches to allow:

• The free flow of drainage • The prevention of rubbish and debris carried by the drainage water being trapped at the base

of equipment or piping. • The prevention of equipment such as electric wiring becoming submerged.

FIGURE 6 demonstrates steel profiles supporting above a head control floor:

• pumps • piping • electric trunking

By contrast, FIGURE 7 demonstrates a head control with a level floor where the drainage is impeded. As a consequence of the level floor, together with the electric trunking not being raised above the floor, the electric cables inside the trunking are flooded as shown in FIGURE 8.

FIGURE 6. PUMP, PIPING AND ELECTRIC TRUNKING ELEVATED ABOVE HEAD CONTROL FLOOR


FIGURE 7. A LEVEL HEAD CONTROL FLOOR WITH INADEQUATE DRAINAGE

FIGURE 8. PARTIALLY SUBMERGED ELECTRIC CABLE TRUNKING


1.5.2. TANKS 1.5.2.1 TANKS – IRRIGATION STORAGE All pumps in a head control should have a flooded suction supplied from a covered bulk storage tank. The size of the tank should be determined by how many days’ total water need to be stored at one time. Do not use a negative suction.

FIGURE 9. BULK STORAGE TANK FOR IRRIGATION WATER

If the suction pipe unavoidably has high points where air can be trapped, fit a suitable one-way-out air valve at the high points.

FIGURE 10. ONE-WAY-OUT AIR VALVE FITTED TO A SUCTION PIPE


1.5.2.1 TANKS – FERTILISER STORAGE Fertiliser storage tanks must be made of a suitable chemical resistant material to hold the correct specific gravity: normally SG=1.4. They must be mounted on a fertiliser storage tank ‘island’ 600 mm above the dosing unit and encircled by a retaining wall that will catch the spillage of an entire tank in the case of an emergency.

FIGURE 11. FERTILISER STORAGE TANKS ON A WALLED ‘ISLAND’ 1.5.3. PIPING, PUMPS AND EQUIPMENT 1.5.3.1 PIPING 1.5.3.1.1 uPVC PIPING Class. South African PVC piping manufacturers do not make a range of PVC piping according to any given mechanical strengths, only according to pressure ratings. Piping in a head control is not buried and so its strength against physical damage must come from its pressure rating. Regardless of a lower operating pressure, a pressure rating of Class 12 should be used. Pipe connection. When joining pipes, only use solvent-weld joints; not integral pipe-end sockets (rubber ring type). If integral pipe-end piping has been purchased, cut off the integral pipe-end sockets and replace with solvent-weld sockets. PVC Pipe clips. Piping should be fastened to the steel profiles or to the walls with PVC pipe clips. FIGURE 6 demonstrates PVC pipe clips fastened to elevated steel profiles. FIGURE 12 demonstrates PVC pipe clips fixed to a wall of a concrete trench.


FIGURE 12. PVC PIPING FASTENED TO THE WALL OF A CONCRETE TRENCH Do not encase piping in concrete as shown in FIGURE 13. Repairing piping or fittings attached to that piping is difficult and may involve reconstruction with a two or three-day wait for concrete to dry.

FIGURE 13. PVC PIPING ENCASED IN CONCRETE


Piping should be raised above the floor at a height of 100 mm with steel profiles 1m apart.

FIGURE 14. CONCRETE TRENCH - SPACE STEEL PROFILES 1m APART

FIGURE 15. CONCRETE TRENCH - RAISE THE STEEL PROFILES ABOVE THE FLOOR ON STAINLESS STEEL THREADED ROD


FIGURE 16. CONCRETE TRENCH – COVERED WITH STEEL GRID 1.5.3.2 PUMPS AND EQUIPMENT Pumps and equipment must be placed so that there is adequate access for day to day operation as well as for service as shown previously in FIGURE 2. 1.5.3.3 ELEVATED MOUNTING OF PIPING, PUMPS AND EQUIPMENT All equipment should be elevated above the levels of the floor and the concrete trenches to allow:

• The free flow of drainage • The prevention of rubbish and debris carried by the drainage water being trapped at the base

of equipment or piping. • The prevention of equipment such as electric wiring becoming submerged.

This raising of equipment and piping also facilitates ease of cleaning the floor with a broom or spraying with a hose. FIGURE 15 demonstrates steel profiles supporting piping above the bottom of a concrete trench. The mounting of pumps and electric trunking was dealt with previously in FIGURE 6 which demonstrates steel profiles supporting these above a head control floor. Piping is normally mounted on 20 mm x 40 mm steel profiles as shown in FIGURE 17. Pipe clips are fixed using self-drilling screws drilled straight into the steel. Other equipment such as pumps is normally mounted on 40 mm x 40 mm steel profiles as shown in FIGURE 18. In this case, the profiles are slotted to fit bolts, enabling moving and adjusting the position of equipment when lining-up.


All Netafim dosing units are already raised above the floor by being mounted on frames with adjustable feet. No further equipment is required. See Section 1.3 Marketing – Product Overview in the CMT Manual.

FIGURE 17. GALVANISED STEEL STRUT – 20 MM X 40 MM

FIGURE 18. GALVANISED STEEL SLOTTED STRUT – 40 MM X 40 MM WITH 14 MM WIDE SLOTS


1.5.3.4 EMERGENCY FERTILISER INJECTION Always have a back-up to the dosing unit to inject fertiliser manually in the event of an emergency. A venturi bridge such as the one in FIGURE 19 can be plumbed so that its upstream motive flow is from the mainline and the lower pressure for the downstream is created by plumbing the downstream into the suction of the irrigation pump. If this method is used, the motive flow of each venturi including the suction flow of the venturis must be added into the total flow of the irrigation pump.

FIGURE 19. A VENTURI BRIDGE AS A FERTILISER INJECTION BACK-UP


1.5.4. ELECTRICAL

Earthing and surge protection is not handled under General Installation. Due to its complexity and importance, it is handled in a separately in Section 1.6 Earthing and Protection of the CMT Manual.

1.5.4.3 CONTROL PANEL Some features of the main electric control panel in a head control are standard or common with manufacturers; others are not. 1.5.4.3.1 CONTROL PANEL - IRRIGATION Netafim recommends that the following features are included in a head control’s control panel.

• Main isolator. • Emergency stop – Kill-switch. Additional emergency stop buttons should be placed

strategically around the head control, depending on the head control’s size. • Main circuit breaker for the control panel. • Incoming voltage surge protection to shunt to earth, one per phase. • Voltmeter with 3-way switch in the case of 3-phase installations. • 24 VAC 75 VA transformer with 24 VAC output to DIN rail connections. • Phase failure protection for the panel and a DIN rail dry contact normally open relay. This

relay will close in the event of a power failure and can be used to put the controller into ‘External pause’ until the power resumes. See Section 3.2.8.3 Digital Input of the CMT Manual.

• Earthing busbar. • Low level protection with low level switch in the bulk storage tank / reservoir. • Controller supply from DIN rail terminal connectors through 20A 230VAC MCB. • To each low voltage output (motor):

o MCB. o Overload protection. o Hand-off-auto switch. o Ammeter. o DIN rail connections:

24 VAC relay with DIN rail terminal connections if started by the NMC controller

Pressure switch with DIN rail terminal connections if started by pressure drop (misting / cooling)

• Splash proof 16 A 230 VAC plug socket through 20 A MCB. • 230 VAC output to 1 000 VA UPS.

NB


FIGURE 20. EXAMPLE OF AN ELECTRIC CONTROL PANEL FOR A HEAD CONTROL Every individual electric item of equipment in the head control must have its own manual isolator switch within reach of that item; without the need to go to the switchboard to switch-off its power.

FIGURE 21. EXAMPLE OF A PUMP WITH ITS OWN ISOLATION SWITCH IN CLOSE PROXIMITY


1.5.4.4 GENERAL WIRING In both irrigation and greenhouse installations, the CMT technician would not generally undertake the low voltage wiring (LV - 50 VAC to 1 000 VAC), which would be done by a qualified electrician. He would though do extra low voltage wiring (ELV - less than 50 VAC or less than 120 VDC). As it is so closely linked to earthing and surge protection, wiring is handled separately in Section 1.6 Earthing and Protection of the CMT Manual. All wiring must use formal wireways. ELV conductors may not share the same wireway as LV conductors. There should be a minimum distance of 10 cm between such wireways. Communication wires should preferably not share the same wireway as ELV conductors and may never share the same wireway as LV conductors. All wireways that run along the floor must be raised away from the floor as demonstrated in FIGURE 6.

Documents

CMT MANUAL - Netafim · CMT Manual offers guidelines the general installation of CMT and in directly related equipment. It is not comprehensive but covers aspects that in the experience