Text for tenders: Rittal air-circulating climate control system (CRAC)


Rittal air-circulating climate control system (CRAC)

for operation with water-based cooling medium



Size 1 (23 kW)  up to size  4 (118 kW)



One-piece air-circulating climate control enclosure

unit for recirculating air operation for use in Data

Centres and other IT operational environments. The

airflow direction inside the unit is from top to

bottom.  The supply air is blown out in the raised

floor.



Enclosure



The enclosure is designed with a twin wall cladding

and rolled frame construction.

The steel section is additionally provided with a coat

of lacquer.

The corner connections are welded. All doors are

sealed with all-round foamed-in PU seals. The twin

wall is provided with an internal 30/45 mm thick

acoustic and  thermal insulation which is fire-proof

and complies with building material class A1 to DIN

4102.



Maintenance is exclusively made from the front via the

front doors.



The outer lining of the rear and side panels consists

of 1.5 mm dipcoat-primed sheet steel. The visible side

is powder-coated in textured RAL 7035 (light grey).



The construction design, colour and surface structure

of the enclosure are in line with the Rittal server

racks based on the well proven Rittal TS 8 enclosure.



The inner lining of the enclosure consists of hot-dip

galvanised sheet steel, the zinc layer is at least 275

g/m².  The inner linings on doors and rear panel have

a material thickness of 1 mm.



Extracted air connection

Free air suction at the top without any further duct

components.



Base frame

The base frame is equipped with vibration damping feet

Adjustment range for compensating the height when

connecting to the raised floor approx.  50 mm.



Filtering

The air filter in the unit suction area is designed as

cassette filter and placed on the cooler.

Filter class is G4 to EN 779. Maximum filtration

efficiency is ensured due to the overall construction

selected. The high filtration efficiency offers a

higher protection of material and persons.



By using cassette filters with a plastic fibre frame

the filter surface is maximised. An all-round seal is

on the filter clean air side.



The filter medium consists of fibre-glass web, folded

in a cone shape (V).

A clean air side integrated support grid for

stabilising the folding. The maximum dust storage

capacity and minor pressure loss are achieved by a

large efficient filter surface.



The position of the filter ensures good access and

front filter exchange.



Electrical filter and airflow monitoring via a common

pressure sensor.



Cooling (cold water cooling CW)

Membrane heat exchangers as cold water cooler for

external coolant supply consisting of copper pipe with

high performance membranes made from aluminium

including partitioning manifold made from copper in a

sturdy frame of 2 mm aluminium. Tray for collecting

condensate, can be removed and cleaned, made from

rustproof anodised aluminium (AlMgSi).



Internal condensate piping with self-filling siphon

consisting of a  40 mm high temperature resistant

tube.



Cold water tube group with two-way mixing valve

positioned in the return, complete with mounted

actuator 24 VDC/50 Hz. Drive included in basic unit.

Piping with flexible foam insulation, connecting

sleeves and air relief valve.



Medium connections

The cold water tubes and the condensate discharge are

led to the bottom out of the unit.



Fan unit

The fan for the airflow direction inside the unit from

top to bottom is positioned in a fluidic positive

manner in the base frame.



Directly driven, single-sided suction high performance

radial fan in reinforced design, without spiral

casing, with stable pressure-volume flow

characteristic. The fan rating is made on optimum

operating point for highest efficiency.

The fan/motor unit is mounted in a supporting

structure and can slightly be withdrawn  forwards for

maintenance purposes.

The rotor has blades of aluminium that are bent

backwards and is statically and dynamically balanced

with a balance quality G 6.3 to DIN ISO 1940.



The fan driving motor works on the external rotor

principle in compliance with VDE 0530, part 1 and is

designed as EC DC motor. The motor is integrated in

the  wheel. The arrangement in the airflow ensures an

efficient motor cooling. The shaft is located in the

ball bearing in accordance with DIN 625 with permanent

lubrification.

The service life of the bearing is 20,0000 . 30,000

operating hours. The motor is ISO class "F" and has

protection category IP 44.



The electronic commutation unit which is necessary is

placed directly at the motor within the airflow and is

used for infinitely variable speed control of the DC

fan motor.



In the scope of commissioning a simple setting of the

volume flow is possible. The electronic commutation

unit has a set value input 0 . 10 V for the automatic

control of the volume flow via an external controller

(DDC).  Integral EMC filter ensure compliance with EMC

limits to  EN 50011-B.





Electrical part

Connection voltage 3 phase/N/PE, 400 V

+-10 %, 50 Hz.



The electrical part is  separated from the airflow and

equipped with a acrylic glass security cover. Design

according to the relevant EN or VDE regulations. All

components necessary for operating the cooling unit

are mounted on a mounting plate in a clearly arranged

way. Operation is made from the front. The control

circuit is rated with a low voltage of 24 VDC as PELV

to VDE 0100 part 410.



Special features,,

Operating panel of control for display of operating

and failure messages in the front door of the climate

control unit . Clear arrangement by optimising the

installation components  - Fuse free contactor-motor

protection combination . Screwfree terminal strip for

more rational and secure wiring . Potential-free

operating (NO contact), maintenance and failure alarm

(NC contact) . Clearly arranged documentation in CAD-E

plans . Labelling of installation components according

to item numbers in the circuit diagram . Terminal

connection diagrams with indication of all external

cables.



Control

Each cooling unit is equipped  with an autarkically

working DDC controller.

The integral pcs+ control is optimised for air and

climate control technology.



A semigraphic and backlit LCD display inserted in the

door is used as operating unit. The screen resolution

is 132 x 64 pixels, 8 lines with 22 characters.

The text output is in German and can be switched to

English.

Setting of system parameters or set values is possible

via 2 different password levels. Operation is made via

6 keys.





Exhaust air/ supply air cascade control with the

following functions:



-,,Monitoring of the built-in components ,,,,

-,,Setting and display of  EC- fan load

-,,Master/Slave change-over (up to16 units).

-,,Automatic re-start of the unit with  adjustable time

delay.

-,, UPS operation (without heater and humidification)

-,, Adjustable  temperature and humidity set values

-,, Adjustable temperature and humidity limit values

-,, Actual values of temperature and humidity

-,, Date and time

-,, Manual operating level

-,, Collective fault signal

-,,Alarm record of the last 10 alarms with date and

time.

-,,Alarm messages: Airflow failure, filter pollution,

limit alarms of temperature and humidity, disturbance

of heater and humidifier if available

-,,Minimum limit of air supply via cascade







The failure of one DDC station  does not have any

influence on the operational reliability of other lDDC

stations linked with it.



Documentation included inside the unit.

Language: German or  English

Quantity: 1 x CD, 1 x paper



OPTIONS AVAILABLE:



Base frame trim panel (not included)

Covering the difference of raised floor to component

shelf when raised floor heights < standard dimension.

Dimensions and design correspond to the standard. The

trim panel consists of 1 mm hot-dip galvanised sheet

steel. The visible surface is finished with a

powder-coating in RAL 9005 (black).  Removable front

part for easy fan maintenance.



Electric heating (not included)

Electric heating consisting of  plain ended pipe

heating rods made from stainless steel. Triple

protection and constant control (0-10 V) from the

basic unit. Fitted in airflow direction behind the

cooler.



Vapour humidification (not offered included)

Vapour self-humidification integrated in the enclosure

including single-stage control with a precision of +/-

10%.



The humidifier is suitable for standard drinking water

quality with a conductivity of 300 - 900 µS/cm. The

steam cylinders are disposable. A steam lance made

from copper is specially adjusted to the steam

generator and integrated in the unit.





Interface unit RS485  (not included)

Plug-type serial interface card with  RS 485

connection to the following  BUS systems: CAREL-Bus or

MOD-Bus



Interface unit RS485-BAC (not included)

Plug-type serial interface card with  RS 485

connection to the following BUS-Systeme: BACnet

(BACnet over RS 485)



Interface unit LON (not included)

Plug-type interface card for connection to LON-Bus



Web server card (not included)

Plug-type interface card with RJ45 connection for

data exchange via Ethernet, BACnet over ethernet

or SNMP.



Further options available on request.



The enclosure can optionally be supplied in RAL 9005.



Manufacturer: Rittal
Type: Rittal air-circulating climate control system (CRAC)   SK 3301860
or equivalent


Quantity  Unit         Price Each                 Price Total
   
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