Pahwa Group Delair RD Series User manual

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Foreword
Welcome to the Delair family !
Thank you for opting for the Delair Dryer.
This manual is dedicated to the principle that industrial machinery must be understood in order that installation
and operation can proceed successfully. It assumes that the machine application is proper and that appropriate
Air Dryer model has been selected.
The refrigerated type Compressed Air Dryer has been manufactured with care to give you excellent service. The
Air Dryer has been manufactured to the designs and engineering of Delair , the world leaders in this field.
Ultimate customer satisfaction is generally dependent upon the compromises made during the installation effort.
Your Delair Air Dryer utilises tested engineering principles and has passed through inspection for quality of
workmanship and function.
Since we have no control of the shipment of our product after they leave our plant, it is suggested that the
machine be thoroughly checked inside out to be certain that no damage has been incurred during shipment.

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INDEX
S NO
TOPIC
1
Introduction
1.1 About refrigeration Dryer
1.2 Principle of operation
1.3 Controls and indicators
1.4 Safety measures
2
Installation and commissioning
2.1 Unpacking
2.2 Inspection
2.3 Installation - types
2.4 Placing the equipment
2.5 Installation
2.6 Electric connection
3
Operation
3.1 Start up
3.2 Switching on and off
3.3 Fault indication
3.4 Safety measures & improper methods of Operation
4
Maintenance
5
Trouble shooting
6
Drawings
6.1 Unit outline
6.2 General arrangement (G.A.)
6.3 Electrical wiring diagram
6.4 Flow sketch
6.5 Foundation detail
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Annexure
LOG SHEET

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INTRODUCTION
This dehumidifying Refrigeration type Compressed Air Dryer consists of the following three main components :
Refrigeration system
Refrigeration compressor
Air cooled condenser
Liquid receiver
Filter Dryer
Automatic expansion valve
Hot gas by pass valve ( as applicable )
Liquid separator
Insulated Heat Exchanger contains :
Air to refrigerant heat exchanger
Air to air heat exchanger
Moisture Separator
Electrical :
Microprocessor based delsmart display
Control PCB
Sensor
Water separator is an automatic drain separator mounted inside the Dryer. The water being separated gets
collected in the bowl, which is periodically drained automatically through a drain valve. A manual drain valve is
also provided as an additional feature.

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1.1 About RD series Compressed Air Dryer
Figure 1 will help you to identify various components of the RD series Compressed Air Dryer along with various
safety and controls
Figure 1

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Microprocessor based delsmart card –Air Cooled
FAULTS
PRESSURE
HIGH
LIQUID
SEPARATOR
DRYER
FILTER
COMPRESSOR
AUTO DRAIN
SEPARATOR
WATER
VALVE
EXPANSION
SYSTEM ON/OFF
POWER ON
COMPRESSOR
OVERLOAD
FAILURE
AUTO-DRAIN
HIGH
AMBIENT
HIGH INLET
AIR TEMP.
M
LIQUID
RECEIVER
SIGHT
GLASS
FAN
CONDENSER
RD Aircooled
Dew Point. 4°C
HEAT - EXCHANGER
AIR
HOT GAS
BYPASS
VALVE
RD SERIES
delair

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1.2 Principle of Operation
Compressed air to be dried is led into the Dryer through "inlet" by means of a leak proof pipe
connection. This air passes through the evaporator coil in the heat exchanger. Here the air
temperature is reduced to about 4 to 6°c resulting in condensation of moisture present in the
air. This air with the condensate is made to pass through the water separator, where the
condensed water is collected in the separator bowl. The dried air (free of moisture) comes
through the outlet point . The dew point indication on electronic display card (Microprocessor
based delsmart card) is digital , showing the air temperature just at the water separator point
thus indicating the actual dew point.

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1.3 Controls and Indicators
Below figure will help you to identify the control and indicator of the Dryer
The electrical consists of :
Miniature Circuit Breaker (MCB)
Microprocessor based delsmart card
Power Supply Card (PCB)
Control contactor for comp. On/Off
Starting kit for compressor (For 1Phase supply)
High pressure switch
Low pressure switch (w.r.t Dryer model)
Fan control pressure switch

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High pressure fault indication
indicates the Dryer when
compressor discharge is high
condition Then high pressure switch
contact are open & compressor off .
Compressor overload fault
indication
Indicates the Dryer when
compressor Are overheating or low
gas condition
High ambient fault indication
Indicates the Dryer when ambient
Temperature high from the set point
Auto drain failure fault indication
Indicates the Dryer when auto
Drain valve clogged
High inlet air temp. Fault indication
Indicates the Dryer when air inlet
temp. High from the set point

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1.4 Safety measures
For your safety, the RD series Compressed Air Dryer are equipped with all necessities for safety and can be
operated continuously.
Miniature circuit breaker
( MCB )
MCB is located in the control panel box. It is help to protect
our Dryer unit against flow overcurrent.An Overcurrent
(insert MCB image) can be either an overload current or a
short circuit (insert MCB image)
High pressure control
switch
Pressure control switch is located in the field. In addition to
pressure control switches for refrigeration system have
pressure controls. Pressure control switch directly affect the
main mass flow of the refrigeration circuit by opening &
closing (insert pressure control switch image)
Fan control pressure
switch
Use on the high pressure side to a variable speed fan control
for ensuring that the condensing pressure does not drop too
low, especially in cold weather. (insert fan pressure control
switch image)
Single phase preventer
( motor protection relay )
( in case of 3 phase
supply unit )
Is located in the control panel box. It is help motor protection
in Following conditions :-
Overloading condition.
Phase failure condition.
Phase reversal condition
Unbalanced current condition
Dry running condition
(insert MPR image)
Earthing point
System earthing is essential to the proper operation of the
system, whereas equipment earthing concerns the safety of
personnel and plant. A key function of equipment earthing is
to provide a controlled method to prevent the build up of stat-
ic electricity, thus reducing the risk of electrical discharge in
potentially hazardous environments. Generally, a resistance
to earth of less than 10.6 ohms will ensure safe dissipation of
static electricity in all situations.

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2 . Installation and commissioning
2.1 Unpacking
Unpack the machine carefully, remove the top and side panels of the packing case. Remove the thermocol
panels from around and top of the unit. Remove mounting bolts clamping down the unit to the wooden base of
the packing and gently lift the machine free from the pallet. Remove the side steel panels by unscrewing the
screw & clean the interior of the machine, lock back the side panels in position. The machine is now ready for
installation.

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2.2 Inspection during pre commissioning
S. no.
Particulars
1
Check cooling water inlet temp ( deg c) and pressure ( kg/cm2)
2
Check all the electrical and mechanical connections
3
Check incoming power supply (220 v or 415 v ac /50 hz)
4
Check earthing vs neutral (0 to–1v)
5
Check setting of phase sequence relay
6
Check the capacity of Dryer and Compressor
7
Check all connection of air and water supply
8
Check for indoor installation and proper ventilation
9
Check air compressor condensoris not facing the Dryer

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2.3 Installation Option
Option A - Dryer ahead of Air Receive
Flow through Dryer = maximum flow of compressor
Inlet temperature Dryer = outlet temperature of after cooler
Option B - Dryer after Air Receiver
Flow through Dryer can be more than maximum flow of Compressor
Inlet temperature Dryer lower than outlet temperature of After cooler
Filter installation Considerations
Installation proposal with Refrigeration Dryer

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2.4 Placing the equipment
We recommend a minimum 600 mm of space be provided for future service and proper air
ventilation. Also ensure that ambient and other inlet parameters are as per design.

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2.5 Installation
Install the machine at a level solid base taking care that front and back of the machine is having free access to
the ambient air. Since the efficiency of the Dryer is directly related to the ambient temperature, air inlet
temperature and air pressure. It is very essential that the Dryer be installed in a room having sufficient
ventilation.
A suitable moisture separator must be installed just before the Dryer inlet or before the pre filter, if one is being
sold along with the Dryer. For best results condensed moisture/oil etc. Must not be allowed into the Dryer inlet.
Air from the compressor is to be connected to the Dryer inlet via moisture separator / pre filter in that order }
Connect the inlet and outlet points ( figure 2.2 ) to the respective points in the pipe lines, all the pipe
connections should be leak proof and such that these do not stress the Dryer outlet and inlet pipes.
Figure 2.2 figure 2.3
Check the manual water drain valve ( figure 2.3 ) and ensure it to be closed. Your Dryer is now ready for
operation. Connect the Dryer main lead to 220v. Ac supply through an automatic voltage stabilizer
{importantly of suitable rating in case the same is desired due to heavy fluctuation in the load.
Important note –
1. We recommend a minimum 600 mm of space be provided for future service and proper air ventilation.
2. Also ensure that ambient and other inlet parameters are as per design.
3. UNIT Should be properly earthed for its smooth functioning.

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2.6 Electric connection
Voltage option
220 volt ac, single phase, 50hz
Std.
415 volt ac, three phase, 50hz + n
Std.
110 volt ac, single phase, 50hz
Other option
415 volt ac, three phase, 50hz w/o n
Other option
System operating on other voltage can be supplied on request, please check the name plate for correct voltage,
number of phases and frequency
Wire & cable sized can be selection on the basis of maximum amperage by electrical items
3 phase wire connection
Single phase wire connection
Caution
Electrical connection should be made by a qualified electrician only.

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3. Operation
3.1 start up
Initially power on led is On. Switch On and start from the system On/Off switch. The switch itself is of illuminative
type. It glows and the machine starts. The air to be dried is now opened. The digital display on mimic display
is showing the inner temperature which is close to the ambient at the start. In about ten minutes time the dew
point will come down to about 4 to 6 ° c and will stabilize. Microprocessor based Delsmart card is also showing
operating status.
The faults i.e. Compressor overload, Gas high pressure, Auto drain failure will be indicate on electronic display
card (Microprocessor based Desmart card) in faults block. It will be on `On’ position , if fault has come and not
been removed/ attended. The machine is a continuous working type and its compressor keeps running and trips
if exceptional overload occurs. If the compressor trips due to overload or power failure it will restart after five
minutes of pressure equalization. If system trip due to gas high pressure then given fault should be acknowledge
by client & restart dryer from system On/Off switch.
The condenser fan is regulated through a pressure switch and keeps switching "On and "Off" depending on the
ambient temperature and amount of air being dried. Lower ambient and lower load on the machine stops the
fan. The fans runs continuously at high ambient and near full loading of the machine.
Warning:
1. The Microperocessor based Delsmart card is factory set and password protected and need not to be
cannot be changes at site.

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3.2 switching on and off:
Switching on:
3.2.1 Switch on the “System On/Off” illuminating switch. Switch glows and the machine starts.
3.2.2 Open the inlet of process air that requires to be dried.
3.2.3 The digital display on Microprocessor based Delsmart card is showing the inlet temperature, which is
close to the ambient temperature at the beginning. In About ten minutes time the dew point will come down to
about 4 to 6 °c and will stabilize.
3.2.4 Microprocessor based Delsmart card is also showing operating status.
Switching off:
3.2.5 Switch off the system On/ Off switch.
3.2.6 Switch off the MCB on the equipment.
3.2.7 Remove the plug from the socket or if the supply cord is connected to the MCB in the fixed wiring, switch
off the MCB.
3.3 Faults
Five types of faults, i.e. High pressure, Compressor overload, High inlet air temperature, High ambient / water
temperature, Auto drain failure will be indicated on electronic display card (Microprocessor based Delsmart card)
in the faults block. It will be in `on’ position, if fault has occurred and has not been removed/ attended to. Refer
to troubleshooting, for necessary action.
1. High pressure fault: compressor discharge pressure is high.
2. Compressor overload fault: the machine is a continuous working type and its compressor keeps running
and trips if exceptional overload occurs. If the compressor trips due to overload or power failure it will
restart after pre set intervals.
3. Auto drain failure fault: auto drain is not working. Refer to daily preventive maintenance schedule, 9
4. High ambient fault indication due to ambient temperature high from the set point
5. High inlet air temp. Fault indication due to air inlet temp. high from the set point

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3.4 Safety measures & improper methods of operation
This refrigeration type compressed Air Dryer is provided with many safety features for protecting both the
operator and the equipment as follows:
1. Prevention of electrical shock:
Supply disconnection: in order to prevent risk of an electric shock, the supply to the equipment should be
disconnected before opening the equipment for service/ maintenance. The equipment should be disconnected
from the supply:
By withdrawing the plug from the socket or
If the supply cord is connected to the MCB in the fixed wiring of the building, the MCB should be switched
off. It is recommended to physically detach the supply cord from the MCB in the fixed wiring of the building.
Switch off the MCB mounted on the equipment.
Protective earth: the equipment has a protective earth (pe) terminal and the power cord has pe conductor, to
ground harmful currents to earth, in case of an insulation failure. To prevent hazard of an electric shock, it shall
be ensured that the fixed wiring of the building and the equipment are properly earthed. Whenever connections
are being made to the fixed wiring, connection to the pe conductor shall be established first, neutral conductor
second and phase/ line/ hot conductor last.
2. Protection of equipment:
Equipment has been provided with an MCB of 230/415v both as a supply disconnecting device as well as over
current protection device. In case of replacing the MCB, it shall always be replaced only with standard MCB of
230/ 415v. It is not uncommon to replace MCB of incorrect rating, and if the current rating is low there will be
nuisance tripping and if the rating is high, the MCB will not trip and the protection is lost.
High pressure switch: protection device, provided in the refrigeration cycle, to automatically trip the equipment
when the refrigerant gas discharge pressure exceeds the limit. Users should not disturb the safety limit setting.
3. Other, common improper methods of installation and operation:
1. Installation of equipment, without adequate ventilation space of a minimum 600mm around the equipment,
which affects the performance and renders regular maintenance difficult.
2. Not maintaining the required ambient temperature, water temperature and air inlet temperature and pressure
for which the equipment is designed for which will affect the performance of the equipment.
3. Installing the Dryer in an excessively dusty, corrosive environment, resulting choked condenser and
consequential low performance and excess power consumption.

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4 . Maintenance
Maintenance schedule of refrigeration type Dryer
Daily
Drain the condensate from the moisture separator and air receiver ( figure 4.2 )
Function of compressor
Weekly
Working of fan
Monthly
Mounting bolts of the compressor, condenser and vla ( figure 4.1 )
De scaling of water cooled condenser
Yearly
Quantity of refrigerant gas
( figure 4.1 )
( figure 4.2 )