When installing the air conditioner in a small server room, often in order to save finances and space, they use not expensive expensive precision equipment specially designed for this, but ordinary household split-systems. But even in such server-side equipment, rather stringent requirements are imposed on the equipment: guaranteed maintenance of the required temperature, year-round uninterrupted operation, high degree of reliability.
Conventional air conditioners can not operate with a negative temperature outside. In such conditions, the condensation pressure drops sharply, as a result, the liquid refrigerant can enter the compressor crankcase. In addition, oil may be thrown from the crankcase into the system. All this leads to frosting of the indoor unit of the air conditioner, reduction of its performance and rapid compressor failure. If the drainage system goes outside, then in extreme cold there are problems with the removal of moisture from the air conditioning system. To eliminate these drawbacks and ensure year-round use, the equipment is being finalized with a winter kit.
Installing only one air conditioner responsible for the server room assumes very big risks,
There are two ways to reserve capacity. At 100% redundancy, two identical air conditioners of the required cooling capacity are installed, and after a certain period of time (as a rule, by the day), these air conditioners will change roles. Another redundancy option is 50% capacity redundancy: when three devices are installed in the server room, each with a capacity of half the required cooling capacity. Two devices work simultaneously, and the third is idle. The rotation of air conditioners is carried out sequentially, that is, in the long term, all air conditioners will work for about the same number of hours. And in fact, and in another case, uniform wear of equipment, emergency activation in the event of a malfunction of one of the air conditioners, or simultaneous activation of all when the temperature rises above the set, and the possibility of carrying out routine maintenance.
To do this, use special devices, the so-called coordinators of the air conditioner, backup devices and rotation of air conditioners.
The coordinator of the work of air conditioners SRK it is intended for control of the technological cooling systems consisting of two blocks of conditioners. To improve the reliability of the process air-conditioning system, two air conditioners are installed in the room, which work alternately with a specified interval, each air conditioner is capable of removing 100% of the heat load. At any time, one air conditioner works, one is a backup.
SRK is intended for collaboration with blocks of conditioners:
- DAIKIN SPLIT series – through adapters KRP413A1S, AD413A1;
- SKY series from DAIKIN – through adapters KRP4A51 / 52/53/54;
- MIITSUBISHI ELECTRIC units, which include wall blocks MSC-GA20 / 25 / 35VB.
The coordinator of Daikin air conditioners (hereinafter the product or
IBS is a block shown in the figure. The main components of SRK are: – protective plastic case (1): – alarm control relay (2): – control switch (3): – timer (4): – alarm indicator (5): – normal operation indicator 1- air conditioner (6): – indicator of normal operation of the 2nd air conditioner (7); – power supply unit 12 V (8).
Principle of operationIn order to increase the reliability of the process air conditioning system in a conditioned room, two air conditioners are installed, each of which is capable of removing 100% of the heat load. In this case, at an arbitrary point in time, one air conditioner works and the other is redundant. The CPK alternately switches on one of the two air conditioners at regular intervals in order to uniformly develop the air conditioners’ life time. The switching time is set by the timer (4). On the timer, you can set the switching time from 1 hour to 10 days. Upon delivery, the timer is set to switch the air conditioners after 24 hours. When switching the timer through contacts 3. 4 (Figure 2) the circuit of the 1st adapter closes and the 1st conditioner turns on, the next timer switch opens contacts 3. 4 circuits of the 1st adapter and The 1st air conditioner switches off, at the same time, via contacts 6. 7 The circuit of the 2nd adapter closes and the 2nd air conditioner switches on. Further, the switching cycles are repeated indefinitely, until then. while there is a module supply voltage. The KRP413A1S adapters allow switching on and off air conditioners through standard control circuits of air conditioners without disrupting the operation mode. Adapters are installed separately from each indoor unit of the air conditioner. Indicator (6) (
Control unit for reservation and rotation BURR-1 The system is designed to provide rotation and redundancy in a complex of several air conditioners (split systems) that use IR control panels.
The system consists of one base unit (BURR-1) and several executive units (BIS-1), one for each air conditioner. The complex can include up to 15 air conditioners of different models and different manufacturers, combined into two or three groups of arbitrary composition. The actuators, through their IR emitters, turn on and off the air conditioners on which they are installed. The operation is performed at the command of the base unit. Commands from the base unit to the executive are transmitted via radio to a distance of 50 m.
The BIS-1 IR emitters are configured for the on / off signals of specific air conditioners on the base unit, which is equipped with a special IR receiver. Before starting the system on the air conditioners and the base unit set the desired temperature in the room. The system allows you to implement various options for rotation and redundancy of 2 or 3 groups of air conditioners. All settings are made using the interactive menu of the base unit.
- rotation of air conditioners – alternate operation of each of two or three groups of air conditioners to ensure the same resource. The switching interval is set by the user;
- switching the system to a working group of air conditioners in case of failure of air conditioners of the main group with a fault signal. Failure is determined by the fact that the temperature in the room exceeds the specified value. Temperature control is carried out using the thermal sensor of the base unit;
- the inclusion of a backup group or groups of air conditioners with a lack of performance of the main group;
- signal output "Crash" various levels;
- shutdown of air conditioners in emergency situations (for example – in case of fire) and issuing the appropriate signal.
The features of the system are:
- ease of installation that does not require the installation of signal lines between air conditioners;
- the possibility of using heterogeneous air conditioning equipment;
- the possibility of a wide variation in system performance due to the use of up to 15 air conditioners in it without limiting their power;
- the possibility of implementing various rotation and reservation schemes;
- high reliability due to the lack of power switching devices and the need to use the “restart” function of air conditioners;
- ease of setting up the system and visibility of information about its work;
- possibility of increasing the system with minimal costs;
- the possibility of making the basic control unit in an adjacent room.
Controller for server rooms SBR01 Purpose of the system The automatic air conditioner control SBR01 performs the following functions: • maintaining the desired temperature level in the required room by wireless automatic control from 1 to 8 air conditioners • ensuring uniform use of air conditioners by rotating them after a user-defined period of time (4 to 24 hours); • fault signaling (transmission of information to sound and relay output, LCD display, web server); • remote monitoring of the status and control of the system emoy via a web server.
Technical characteristics The automatic control system for air conditioners consists of one central controller SBR01 and from 1 to 8 subordinate wireless RF modules. Each of the RF modules controls one air conditioner. Communication between the SBR01 controller and RF modules is carried out in the unlicensed radio range of 2400 MHz. The range of stable communication between RF modules and the controller directly depends on the operating room. The range of stable communication in open areas is 100 meters.