JPS592811B2 - Automatic control backup circuit in air conditioning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a backup circuit in a central control system that automatically controls an air conditioner.

In the conventional central control system using direct control, as represented by the schematic system diagram shown in Figure 1, all systems are controlled centrally, so if the central control device A fails, the entire system is Generally, each individual control system B has a locally closed backup control circuit C, and the circuit is configured to manually or, in rare cases, automatically switch to the local side. However, installing backup circuit C requires a large amount of equipment cost, and if no backup circuit is installed, the control circuit is only installed on the central control side, which may cause failure of the central processing unit. At times, it was inevitable to cause major confusion.

Also, in direct control from the central processing unit.

One of the features of this system is to reduce equipment costs by eliminating the local control circuit, so the provision of local control circuit equipment for backup is contrary to the purpose of the system, and backup measures have become an important issue. Ta.

This can be said to have made it difficult to adopt a direct control method for automatic control of air conditioning equipment.

The present invention was devised in view of such circumstances, and in the event of an abnormality on the central processing side such as a wire breakage or computer failure, the automatic control circuit from the central processing side is set in advance to predict the abnormal situation. This air conditioning system automatically switches over to the control circuit so that malfunctions can be found and repaired while keeping the pulp damper in the safest condition and preventing major disruption within the building. It attempts to provide an automatic control backup circuit in the device.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 2 shows a circuit according to the present invention for controlling the amount of adjustment steps of a pulp damper, etc., and shows a remote control device CV.
From c, 0N1OFF' Xl jX2 , X3X
Contact group X1a, X2a, X3a of relay group 1 consisting of 4
, X4a and X,b, X2b, X3b.

X and b are each connected to a resistance element of the adjusting composite resistor 2.

This adjusting composite resistor 2 is 9Ω, 18Ω, and 36Ω, respectively.
Ω, 72Ω four resistance elements r1. r2゜r3νr4;
A resistor group R, R having a sum of resistance values of 135Ω is further connected in series.

These resistance values are not equal to each other = constant sequence, i.e. 2
It is constructed to form a series sequence with a common ratio of .

Moreover, each resistance element rljr2, r3, r4, r
1, r2, jr3, and r4, and a relay X1. X2. X3. Both a and b group opening/closing contacts of X4 are provided, and the total resistance value at both ends of the resistance group Rs is 2X135Ω.
is connected to be changed by a partial short circuit.

A controlled circuit for local air conditioning equipment, that is, a pulp control circuit 3 is connected to both outer ends A) and B and the intermediate junction C.
is connected.

In this case, any contact point or 7' (for example, contact group X1atX2a, X3
a, X4 a is closed, and B of the other resistance group R,
If the resistance between C and C is changed and opened by the combination of contacts opposite to the former, the outer ends of both resistors R2R A j B
The resistance value between is always kept at a constant value of 135Ω, thus,
The output from the controlled circuit 3 side is configured so that it can be controlled stepwise into 24 equal parts.

That is, the composite resistor 2 includes an arbitrary number of eight resistive elements r1.
...r4. By combining rl...r4 and parallel relay contacts X, a, X2a... It is variable and has the function of performing multi-stage step control over 16 stages with a circuit configuration similar to that of a normal continuous variable resistor.

When the central control side is in a normal state, the composite resistor 2 is connected to the remote control side by connecting one of the contacts Ryo of the relay Ry, but when the central control device discovers an abnormality at a particular site, it is manually operated. When the circuit is in a no-voltage state due to shutdown or disconnection on the power supply side, and normal instructions cannot be issued from the center side, the relay Ry operates to close the contact Ry.

For example, the circuit is switched to the circuit on the hand control device 5 side including the hand control variable resistor 4 and connected to the controlled circuit (see the position shown in FIG. 2).

) This variable resistor 4 has the same value as the above-mentioned 135Ω as a whole, and can be backed up by freely varying the resistance value taken out by manual operation.

The resistance value is set by an operator who has predicted the unexpected situation and selects a suitable value in advance.

In this way, the controlled circuit 3 switched to the local side receives a control command set in advance by the variable resistor 4, and is backed up only during the period when the automatic control system command is missing.

A local control device 5 (/'i) that performs the above control is installed at the installation site of the pulp damper, etc., and not only functions as a simple backup device, but also connects the built-in remote/local switching switch 6 to the relay Ry K. The controller turns off the KON1 independently from the central control, and also functions as a hand-operated device for automatic air conditioning control equipment during testing and maintenance.

In summary, the present invention is based on a remote control adjustment contact connected to a control circuit that controls the amount of adjustment steps of a temperature, humidity, or pressure adjustment valve/damper, and an adjustment potentiometer input from the contact. A circuit consisting of a control contact for hand control and a variable resistor for control, which is set in advance to a predetermined state to be restored in anticipation of unexpected situations, is connected to the control contact on the hand side when there is no voltage. In the event of an abnormality on the central processing side, such as a disconnection or computer failure, the automatic control circuit from the central control circuit is automatically switched to the local control circuit that has been set in advance to predict abnormal situations. This will maintain the pulp damper, etc. in the safest condition, and will not cause any major confusion in the building, and will also allow the control system to be changed from the local side to the central side after the central side is repaired. This provides extremely useful new effects such as being able to be performed immediately.

[Brief explanation of drawings]

The drawings show an embodiment of an automatic control backup circuit in an air conditioner according to the present invention, in which FIG. 1 is a schematic system diagram of a conventional device, and FIG. 2 is a diagram showing step control of valves, dampers, etc. FIG. 2 is a circuit diagram of the present invention. In the figure, 1 is a relay, X1a, X2a, X3a, X4a. X1b, X2b, X3b, X4b... are the contact points, 2
are composite resistors, rl...r4. rl...r4
is its resistance element, Ry is its relay, Ryoij is its contact,
3 is a controlled circuit, 4 is a variable resistor, 5 is a hand control device,
6 is a remote hand selector switch.

Claims (1)

[Claims] 1. A circuit consisting of a remote control adjustment contact connected to a control circuit that controls the adjustment step amount of a pulp damper for temperature, humidity, or pressure adjustment, and a composite resistor for adjustment that receives input from the contact; A circuit consisting of a hand control contact and a variable resistor for hand control, which is set in advance to a predetermined state to be restored in anticipation of unexpected situations, is connected to a relay that switches the control contact on the hand side when there is no voltage. An automatic control backup circuit in an air conditioner, characterized in that the circuit is connected through an air conditioner.