Netafim NetaJet NMC Operating manual

NetaJet NMC user and installation
manual
Manual version: 1.00
Date of issue: March 2005
Publisher: Netafim
TM (A.C.S.) Ltd.
© Copyright 2003, Netafim
No part of this publication may be reproduced, stored in an automated data file or made
public in any form or by any means, whether electronic, mechanical, by photocopying,
recording or in any other manner without prior written permission of the publisher.
Although Netafim takes the greatest possible care both with its products and the
associated manuals, there may be deficiencies in them.
Netafim will not however accept responsibility for damage resulting from the use of
Netafim products or damage resulting from the use of this manual. Netafim also
reserves the right to make changes and improvements to its products or to the
associated manuals without notice.

NetaJet Dosing Unit
Table of contents
Table of contents.........................................................................................................2
Introduction..................................................................................................................4
What is the system intended for...................................................................................4
Advantages..................................................................................................................4
NetaJet ........................................................................................................................4
Applications .................................................................................................................6
Structure & Specifications:...........................................................................................7
NetaJet dosing unit basic materials: ............................................................................7
Schemes and Drawings:..............................................................................................7
Inlet / Outlet Dimensions..............................................................................................9
Water supply:...............................................................................................................9
Fertilizer dosing capacity ...........................................................................................10
Installation..................................................................................................................11
Environmental conditions...........................................................................................11
Hydraulic installation..................................................................................................12
General requirements................................................................................................12
NetaJet Installation Instructions.................................................................................13
Electrical and controller installation............................................................................188
Electrical Grounding...................................................................................................188
Supply power.............................................................................................................20
PH Transmitter & Sensor connection and calibration ................................................22
EC Transmitter & Sensor connection and calibration ................................................24
NNM-64 Installation - Getting started.........................................................................27
NetaJet Commissioning.............................................................................................29
Installation requirements............................................................................................30
Pressure sustaining valve..........................................................................................30
Maintenance..............................................................................................................31
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NetaJet NMC User & Installation Manual Table Of Contents
Parts list & Description...............................................................................................32
Venturis & Booster Pump Specifications....................................................................35
Tips for calibrations ………………… ………………………………………………………39
Warrenty And safety...……………………………………………………………………...42
Safety instructions...………………………………………………………………………...42
Installation and maintenance…...………………………………………………………….42
Preparing the stock of acid/lye...………………………………………………………….42
3

NetaJet Dosing Unit
Introduction
This manual details the installation, commissioning and maintenance of Netafim’s
NetaJet dosing units. The aim of this manual is to assist and enable technicians and
skilled growers to install, commission and maintain the NetaJet dosing unit.
What is the system intended for
Netafim’s Netajet dosing units enable growers to precisely control their fertilizer and
acid quantities as well as their irrigation water quantities.
Advantages
Netafim’s next-generation dosing systems meet the most demanding modern irrigation
and fertilization needs. Netafim’s dosing unit based on a precise, efficient Venturi
injector with no moving parts assures reliability and system longevity. For control, the
systems employ unique quick action valves developed specially for the chemical
industry. PH monitoring and control is standard, EC measurement and control is
optional and can be easily added to the systems.
• Fast and accurate fertilizer and acid control.
• Minimum expenses and intervention.
• Attractive price / performance ratio.
• Compact design – reduced shipment coasts.
Netajet
A Netajet injection unit designed to provide accurate fertilizer and acid control with
minimum expense and intervention. Each dosing channel is equipped with a visual flow
meter that can be adjust manually to deliver the required flow rate.
The nominal flow rate of each fertilizer’s venturi injector is 60 Gallon/Hour and the acid
venturi injector is 15 Gallon/Hour.
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NetaJet NMC User & Installation Manual Introduction
Hydraulic principle:
EC
pH
Neta
j
et OPTIONAL
Figure 1- Hydraulic principle
Notice: pH measurement and control is standard nevertheless the systems can
be supplied with EC measurement if required.
5

NetaJet Dosing Unit
Applications
The most common application of the NetaJet is the direct distribution method: the
dosing unit circulates the nutrient solution to the various crop sections.
With this direct distribution method, the NetaJet is only active during Fertigation. The
NetaJet can be used for overhead irrigation, drip irrigation, etc’.
With large areas where the flow rate is greater than 1000 GPM, the fertilizer injection of
60 GPH/channel needs to be verified by the purchaser, as an adequate injection rate.
For Greenhouse and nursery applications where there is a wide range of flow, the
NetaJet can have a turndown of 60% and still maintain a uniform concentration. With
turndowns >60% a mixing tank is required to maintain uniform concentration. i.e.. If the
high rate of flow on the system is 500 GPM, the minimum flow for uniform concentration
is (500 X (1-60%)= 200 GPM).
6

NetaJet NMC User & Installation Manual Structure & Specifications
Structure & Specifications:
This chapter describes the structure of the Netajet dosing unit, its main components,
sizes and dimensions. The role of the various components is explained.
NetaJet dosing unit basic materials:
The NetaJet is equipped with the following components:
• Aluminum frame with adjustable legs.
• All necessary PVC piping.
• Goulds Booster pump used to drive the venturis.
• Venturis and dosing valves.
• Visual flow meters (rotameters) for fertilizer and acid flow indication.
• Switch board with mains voltage components and controller parts.
• Pressure switch to protect the Booster pump.
• pH sensors and transmitters (Ec is optional and can be add easily).
• NMC-64 controller with 24VAC outputs, digital and analog inputs and surge
suppression card.
Schemes and Drawings:
Figure 2 - Netajet Front View
7

NetaJet Dosing Unit
Figure 3 - Netajet Back View
Figure 3 – Side drawing (inches dimensions)
8

NetaJet NMC User & Installation Manual Structure & Specifications
Figure 4 – Upper drawing (inches dimensions)
Inlet / Outlet Dimensions
Netajet
Inlet Diameter 1½ inch NPT male thread
Fertilizer A Outlet Diameter 1 inch NPT male thread
Fertilizer B Outlet Diameter 1 inch NPT male thread
Acid Outlet Diameter 1 inch NPT male thread
Fertilizers & Acid supply ½ inch BSP male thread
Water supply:
The supply water to the NetaJet has to be:
• No more than 72 PSI.
• No less than 30 PSI.
• Constant in terms of pressure (not fluctuating). If there are fluctuations of more than
10 PSI in supply water pressure, a pressure sustaining valve must be installed (see
Pressure sustaining valve).
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NetaJet Dosing Unit
Fertilizer dosing capacity
• Maximum dosage capacity will be achieve in the minimum operating pressure of 30
PSI (in the main line), at this pressure, the dosage capacity per fertilizer channel is
60 Gallon/hour and per acid channel is 15 Gallon/hour.
• The dosage capacity is virtually independent of the operating pressure above the
specified minimum 30 PSI.
• Minimum dosage capacity of a dosing channel is 10% of the maximum dosage
capacity.
• Maximum and minimum dosing capacity can be adjusted per channel via the pin-
valve located on the visual flow meter.
• Motive flow per fertilizer channel is around 700 Gallon/h and per acid channel is
around 235 Gallon/hour.
Notice: Motive and Suction flow of the venturis depends in the inlet and outlet
pressure of the venturi (see venturis table).
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NetaJet NMC User & Installation Manual Installation
Installation
This chapter details the hydraulic and electrical installation instructions for the Netajet
dosing unit. The aim of this chapter is to enable and assist technicians and skilled
growers to install and commission the Netajet dosing unit.
Environmental conditions
The Netajet dosing unit has been designed for installation in service room or a shaded
area.
When installing the complete dosing unit, including water supply, fertilizer tanks, etc’
the following rules must be observed:
1. Install the dosing unit in a shaded area and make sure that it is not exposed to
direct sunlight, especially the electrical cabinet.
2. Install the dosing unit in an area with an ambient temperature of between 40 °F and
105 °F and a maximum relative air humidity of 85 % (without condensation). Make
sure it is properly ventilated.
3. Install the dosing unit in a dry area protected from splashes, direct spraying with
water or chemicals.
4. The dosing unit must be installed on a hard, leveled floor.
5. Ensure that suitable electrical power supply is available in the vicinity of the
installation for connection of the Netajet dosing unit.
6. Ensure that there is an electrical socket available in the Netajet vicinity both for
installation and for maintenance.
11

NetaJet Dosing Unit
Hydraulic installation
There are a few rules and recommendation that must observed when installing the
Netajet dosing units:
General requirements
Water supply
Prior to Netajet installation the following points must be observed and dealt with:
• Filtering:
An 80-mesh filter must be installed before the Netajet dosing unit. Moreover it is
recommended that a filter that removes solid contaminants of more than 500 µm
should be installed before the Netajet. This will significantly reduce the risk of
gradual build-up of contaminants in the area of the pH measurement, venturi inlets,
etc’ and will reduce the risk of malfunctions associated with this.
• Water temperature:
It is important to verify that the irrigation water temperature is always kept in the
allowed values of 40°to 105° F.
• Chemical conditioning:
In case of high levels of bicarbonate concentrations in the supply water it will be
practically impossible to accurately control the pH levels, moreover there will be a
difference between the levels measured by the Netajet to the levels measured in the
field. In this case it is recommended to pre-treat the supply water by means of
acidification. Acid pre treatment of the water is only desirable if the
bicarbonate/"dissolved carbon dioxide" concentration is too high, then injecting acid
into a storage tank can solve the problem. The reaction of the acid with the
bicarbonate will result in the release of CO2. It is essential that the CO2be properly
removed before the water is injected with the fertilizers to prevent it from taking part
in the chemical reactions.
• Pressure:
• Maximum 72 PSI.
• Minimum 30 PSI.
• Constant, not fluctuating; If there are fluctuations of more than 0.5 bar in
supply water pressure a pressure sustaining valve must be installed (see
Pressure sustaining valve)
• Suitable for field requirements.
Fertilizer supply:
• Fertilizer tanks:
In order to ensure maximum and even fertilizer capacity the following rules
must be observed:
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NetaJet NMC User & Installation Manual Installation
• The fertilizer tanks must be installed as close as possible to the Netajet. It is
recommended to keep a maximum pipe length of 10 meters. Nevertheless
there has to be enough space between the fertilizer tanks themselves and
between the Netajet so that inspection and maintenance operations can be
carried out.
• The fertilizer tanks must be at least the same level as Netajet if not higher.
• Piping and fittings for all dosing channels must be kept as similar as possible
in terms of dimensions and length.
• All supply lines for water and fertilizer and output lines for fertilizer and acid
can be plumbed using PVC (Schedule 80 preferred), Flexible PVC hose (must
be protected from UV radiation) or polyethylene hose.
• For acid, the supply lines are normally installed and maintained by the acid
supplier. Teflon is the best material for acid supply lines. PVC and Stainless
Steel are acceptable but have a shorter life. No nylon, brass, galvanized or
steel fittings can be used.
• It is recommended that the suction from the fertilizer tanks be done about 5-10
cm higher than the bottom of the tank. This prevents suction of sediment and
reduces the risk of clogging and blockage.
• Filtering:
It is essential to ensure proper filtering before the Netajet dosing channels; the
minimum filter should be of 120-mesh screen. All sand must be removed from the
water.
• Piping:
The hose connection of the Netajet is suitable for a ½ inch flexible hose. Make sure
the hose used is chemical resistant. It is recommended to tighten the hose with a
stainless steel hose clip.
NetaJet Installation Instructions
• The ratio between irrigation water flow / Bypass water flow should be no less than
1.5 and no more than 100. This is essential because of the solubility of the
fertilizers in the Bypass water flow
Flow through the NetaJet should be calculated as follows:
• Flow per fertilizer channel is around 760 Gallon/h (700 Gallon/h motive flow +
60 Gallon/h fertilizer suction).
• Flow per acid channel is around 250 Gallon/h (235 Gallon/h motive flow + 15
Gallon/h acid suction).
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NetaJet Dosing Unit
• A distance of about 6.5 foot should be maintained between inlet and outlet
connections of the NetaJet to the irrigation mainline (see drawing below).
• It is important to ensure proper turbulent flow between Bypass water and irrigation
water in the mainline. There are a few alternatives to achieve the required turbulent
flow, for example:
• Adding a mixing chamber such as a filter on the mainline (see Figure 6 -
Installation with Filter)
• Adding an injection tube fitted in the inlet and outlets of the irrigation mainline.
• Typically pH adjusting flow is injected upstream of filtration and fertilizer is
downstream of filtration. If products are injected upstream of filtration the increased
flow must be included in filtration design for total flow as the NetaJet flow will be
filtered twice.
water
meter
5 D 6.5 ft
5 ft
Figure 5 - NetaJet Hydraulic Installation
14

NetaJet NMC User & Installation Manual Installation
water
meter
5 D
AC ID
FERT A
FERT B
Figure 6 - Installation with Filter
15

NetaJet Dosing Unit
Typical installation
16

NetaJet NMC User & Installation Manual Installation
17

NetaJet Dosing Unit
Electrical and controller installation
Electrical Grounding
Electrical equipment can be destroyed or slowly damaged by voltage spikes, lightning
hits, etc’. Proper electrical grounding in combination with the NMC-64 internal
protections is essential to protect the system, reduce the risk of damage and prolong its
lifetime.
Correct selection and installation of equipment will protect your system and reduce the
risk of human injury.
Proper grounding provides an easy path for electrical current to return to its source.
A grounding system should tie all non-current carrying conductors to earth ground (0
volts). The grounding system should present a minimum resistance to current flow.
Make sure all items used are in proper condition, for example, a corroded wire clamp
attaching a ground wire to a ground rod might add 100 ohms or more resistance to a
system.
Less than 5 ohm will be considered as a good ground.
A very good ground needs to be supplied using a minimum of 2 grounding rods
and 4 Gauge standard wire connecting the grounds to the NetaJet.
Ground Rods
Ground rods are used to efficiently connect the system to earth where current may be
dissipated in the soil.
• Material:
Ground rods should be copper clad.
• Diameter:
Minimum 5/8”, preferably 3/4”. Generally the larger the rod diameter, the lower it’s
resistance to current flow.
• Length:
Minimum 8 feet, preferably 10 foot. A longer ground rod will reach a soil with higher
moisture content. Moist soil carries current much better than drier soil.
• Single grounding:
It is important that there is only one grounding location where a rod or series of rods
are connected to each other using a ground wire.
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NetaJet NMC User & Installation Manual Installation
Independent ground rods will increase the risk of current, from a lightning strike for
example, being dissipated through one rod and reentering the system through an
adjacent rod.
• Location;
Close to the main circuit breaker panel and in moist soil. For example in an area
that is usually wet from a drip or a low spot where water drains. Make sure the area
is well protected from damage by lawnmowers, tractors, etc’.
• Rod installation
Drive the rod into the earth until about 10 cm (4 inches) is left above grade. If it is
impossible to drive the rod to the proper depth, it is acceptable to lay the rod
horizontally, 2.5 feet below grade.
In case the rod is exposed to damage, for example by lawnmowers or tractors it can
be installed in a hole, about 8 inches deep so that the rod is about 0.3 feet under
grade and 0.3 feet above hole level.
Notice: The National Electric Code (NEC) mandates two ground rods unless you
can show less than 10 ohms resistance with one rod.
Ground Wire
The ground wire is a large copper wire that connects the main circuit breaker panel to
the ground rod.
• Diameter:
Typically, 6-gauge copper standard wire is sufficient. If the wire run is greater than
20 feet, 4 - gauge wire should be used.
The ground wire should be protected from damage by lawnmowers, tractors, etc’. It
should be buried minimum 6 inches under grade for protection and enter the house as
soon as possible. It is important that the wire not be cut; it should remain continuous.
Ground Clamps
Ground wires should not be merely wrapped around a ground rod. Ground clamps are
used to attach a ground wire to a ground rod. The most common clamp is known as an
acorn clamp.
Make sure the ground clamps you select are rated for outdoor use. Do not use pipe
clamps rated for inside water lines or hose clamps to attach the ground wire.
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NetaJet Dosing Unit
Ground connection
What Should Be Grounded?
Any equipment that is or could become energized, even accidentally, should be
grounded. Current from lightning, strikes objects in a random fashion. Accounts of
lightning strikes reveal scenarios most of us could not predict.
Electric circuits should be wired with a 3-wire conductor consisting of hot, neutral and
grounding wires. The grounding wire should be attached cleanly and securely to
devices or systems to be grounded. The other end of the grounding wire should be
attached to the ground bus on the main panel.
Supply power
Installer needs to supply power to NetaJet in conduit with disconnects. The NetaJet
includes power protection for the controller and motor controls for the motor.
Electrical connection to NetaJet divided per 2:
• Controller - 1Phase, 2 amps at 120 VAC with disconnect.
• Booster pump – 2 HP at 240 VAC or 480 VAC 3 phase (optional) with
disconnect.
Electrical connection – 2X240VAC
Main power
t
o
th
e
N
e
t
aJe
t Supply power
to the NMC
controlle
r
Power to the
Booster pump
20