BO-01 EXCHANGE UNIT

(attached to the UBZ-301 Universal Inductive Electromotor Protection Unit)

1 - green LED "On" signalling that power supply exists;

2 - output terminals to the local network;

3 - data reception terminals from the UBZ-301;

4 - data transfer terminals from the BO-01;

5 - power terminals.

APPLICATION

The BO-01 data exchange and transfer unit is designed to provide interface between the UBZ-301 and the local network.

The BO-01 supports the MODBUS protocol in the RS-485 standard. The BO-01 receives the data transferred regularly by the UBZ-301 and records them into its own internal registers.

According to the MODBUS command formats there are two types of registers:

• input registers;
• holding registers.

The data associated with input signals and with the decisions that are made on their base are recorded into theinput registers.

The data associated with the parameters that are stored in the UBZ memory or are set by the UBZ front-panel potentiometer arms are recorded into theholding registers.

According to the ¹4 (input registers reading) and ¹3 (holding register reading) MODBUS commands the exchange unit transfers the contents of the registers to the local data communication network.

Every unit has a specific address recorded in its memory.

The function of the registers :

input register [0] - voltage 1

input register [1] - voltage 2

input register [2] - voltage 3

input register [3] - current 1

input register [4] - current 2

input register [5] - current 3

input register [6] - differential current

input register [7] - shunt conductance

input register [8] - quantity of heat

input register [9] - quantity of heat

input register [10] - the device blocking

input register [11] - heat de-energization

input register [12] - imbalance de-energization

input register [13] - status 1

input register [14] - status 2

input register [15] - status 3

input register [16] - ON-time meter

input register [17] - NA

input register [18] - transfer length from the UBZ-301

holding register [0] - nominal voltage value

holding register [1] - nominal current value

holding register [2] - double overload time constant

holding register [3] - voltage imbalance and current imbalance

holding register [4] - voltage thresholds

holding register [5] - minimum current

holding register [6] - rated current (A)

holding register [7] - a correction to rated current

holding register [8] - nominal heat value

holding register [9] - nominal heat value

holding register [10] - shunt conductance threshold

holding register [11] - ON-time

Notes :

Status registers (6 minor bites) represent the decisions that are made by the UBZ-301

status1 = [ pefU maxU1 maxU2 maxU3 pefU1/2 minU1 minU2 minU3 ]

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pefU - voltage imbalance is present

maxU1 - voltage 1 exceeds the upper threshold

maxU2 - voltage 2 exceeds the upper threshold

maxU3 - voltage 3 exceeds the upper threshold

pefU1/2 - a half of voltage imbalance

minU1 - voltage 1 is below the lower threshold

minU2 - voltage 2 is below the lower threshold

minU3 - voltage 3 is below the lower threshold

status2 = [ pef pfIU Imed< Imed> IZO min1 min2 min3 ]

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pef - current imbalance is present

pfIU - current imbalance is twice exceeds voltage imbalance

Imed< - the current averaged over all the three phases is below the minimum current

Imed> - the current averaged over all the three phases is above the maximum current

IZO - winding insulation breakdown

min1 - the current 1 is below the minimum current

min2 - the current 2 is below the minimum current

min3 - the current 3 is below the minimum current

status3 = [ DDL WKL Q NOFAZ GOODU LK 3F 1F ]

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DDL - the UBZ-301 blocking

WKL - the relay is energized

Q - heat overload

NOFAZ - incorrect phase sequence

GOODU - voltages are normal

LK - leakage current exceeds the threshold value

3F - three-phase mode of operation

1F - single-phase mode of operation

Absolute input values calculation. Voltage calculation.

 

In the 3-Phase mode of operation line voltages (in V) are determined from the following relationships:

V12 = 381* (U1 / U220);

V13 = 381* (U2 / U220);

V23 = 381* (U3 / U220);

where U220 = holding register[0]

U1 = input register[0]

U2 = input register[1]

U3 = input register[2]

In the 1-Phase mode of operation phase voltages (in V) are determined from the following relationships:

V1 = 220* (U1 / U220);

V1 = 220* (U2 / U220);

V2 = 220* (U3 / U220);

where U220 = holding register [0]

U1 = input register [0]

U2 = input register[1]

U3 = input register[2]

Current calculation.

The nominal current (in A) I0 = In* (In% /100) ;

Current 1 in Ampers i1 = (I1 / Ií )* I0

Current 2 in Ampers i2 = (I2 / Ií )* I0

Current 3 in Ampers i3 = (I3 / Ií )* I0

where In = holding register[6]

In% = holding register [7]

In = holding register [1]

i1 = input register[3]

i2 = input register[4]

i3 = input register[5]

Wiring diagram