Carlo Gavazzi DFB01, PFB01 Catalog Page

Specifications are subject to change without notice (20.12.01) 1

Monitoring Relays
Frequency Monitoring
Types DFB01, PFB01

• Over/under frequency monitoring relays

• Measuring if power supply frequency is within set limits

• Measure on own power supply

• Measuring ranges
Voltage: 24 to 240 VAC
Frequency: 50 - 60 Hz

• Separately adjustable upper/lower level on relative

scale

• Adjustable delay on alarm or on recovery (0.1 to 30 s)

• Programmable latching or inhibit at set level

• Output: 8 A SPDT relay N.D. or N.E. selectable

• For mounting on DIN-rail in accordance with DIN/EN

50 022 (DFB01) or plug-in module (PFB01)

• 22.5 mm Euronorm housing (DFB01) or 36 mm

plug-in module (PFB01)

• LED indication for relay, alarm and power supply ON

Product Description Ordering key

DFB 01 C M24

Housing
Function
Type
Item number
Output
Power Supply

DFB01 and PFB01 are pre­cise frequency monitoring
relays. The relays monitor
their own power supply from
24 to 240 VAC.
The advantage of using the
latch function is that the
relay can be kept energized

even after the end of the
alarm condition. Inhibit func­tion can be used to avoid
relay operation when not
desired (maintenance, tran­sitions). The LED's indicate
the state of the alarm and
the output relay.

Type Selection

Mounting Output Measuring range Supply: 24 to 240 VAC

DIN-rail SPDT 50-60 Hz DFB 01 C M24
Plug-in SPDT 50-60 Hz PFB 01 C M24

Input Specifications Output Specifications

Input

Own power supply DFB01: A1, A2 (24 to 240 VAC)

PFB01: 2, 10 (24 to 240 VAC)

Measuring ranges Upper level Lower level

Selectable by DIP-switches
2 Hz range -0.2 to +2 Hz -2 to +0.2 Hz

50 Hz 49.8 to 52 Hz 48 to 50.2 Hz
60 Hz 59.8 to 62 Hz 58 to 60.2 Hz

10 Hz range -1 to +10 Hz -10 to +1 Hz

50 Hz 49 to 60 Hz 40 to 51 Hz
60 Hz 59 to 70 Hz 50 to 61 Hz

Contact input

DFB02 Terminals Z1, Z2
PFB02 Terminals 8, 9
Disabled > 10 kΩ
Enabled < 500 Ω
Pulse width > 500 ms

Hysteresis

2 Hz range ~ 0.05 Hz

10 Hz range ~ 0.25 Hz

Output SPDT relay
Rated insulation voltage 250 VAC
Contact ratings (AgSnO

2

)µ

Resistive loads AC 1 8A @ 250 VAC

DC 12 5 A @ 24 VDC

Small inductive loads AC 15 2.5 A @ 250 VAC

DC 13 2.5 A @ 24 VDC

Mechanical life ≥ 30 x 106operations
Electrical life ≥ 10

5

operations

(at 8 A, 250 V, cos ϕ = 1)

Operating frequency ≤ 7200 operations/h
Dielectric strength

Dielectric voltage ≥ 2 kVAC (rms)
Rated impulse withstand volt. 4 kV (1.2/50 µs)

DFB01 PFB01

2 Specifications are subject to change without notice (20.12.01)

DFB01, PFB01

General Specifications

Power ON delay 1 s ± 0.5 s
Reaction time (input signal variation from

-10% to +10% or from

+10% to -10% of the range)
Alarm ON delay < 200 ms
Alarm OFF delay < 200 ms

Accuracy (15 min warm-up time)

Temperature drift ± 200 ppm/°C
Delay ON alarm ± 10% on set value ±50 ms
Repeatability ± 0.02 Hz

Indication for

Power supply ON LED, green
Alarm ON LED, red (flashing 2 Hz

during delay time)
Output relay ON LED, yellow

Environment

Degree of protection IP 20
Pollution degree 3 (DFB01), 2 (PFB01)
Operating temperature -20 to 60°C, R.H. < 95%
Storage temperature -30 to 80°C, R.H. < 95%

Housing dimensions

DIN-rail version 22.5 x 80 x 99.5 mm
Plug-in version 36 x 80 x 87 mm

Weight Approx. 150 g
Screw terminals

Tightening torque Max. 0.5 Nm

acc. to IEC 60947

Approvals UL, CSA
CE-Marking Ye s
EMC Electromagnetic Compatibility

Immunity According to EN 61000-6-2
Emission According to EN 50081-1

Mode of Operation

DFB01 and PFB01 monitor
the frequency value of their
own power supply.

Example 1

(Non-latching mode - N.D.
relay)

The relay operates and the
yellow LED is ON as soon
as the measured frequency
exceeds the upper set level
or drops below the lower set
level for more than the set
delay time. The relay releas­es when the measured fre­quency comes back within
the upper and lower limits.
The red LED flashes until the
delay time has expired or
the measured value falls off
the limits.

Example 2

(Latching mode - N.E. relay)

The relay operates and the
yellow LED is ON as long as
the measured frequency is
within the upper and lower
limits.
The relay releases and
latches in alarm position as
soon as the measured fre­quency exceeds the upper
set level or drops below the
lower set level for more than
the set delay time. The red
LED flashes until the delay
time has expired or the
measured value comes back
within the limits. Provided
that the frequency has
dropped below the upper
set level (minus hysteresis)
or exceeded the lower set
level (plus hysteresis), the
relay operates when the
interconnections between
terminals Z1, Z2 or 8, 9 are
interrupted.

Supply Specifications

Power supply Overvoltage cat. III

Rated operational voltage (IEC 60664, IEC 60038)
Through terminals:

DFB01: A1, A2 24 to 240 VAC ± 15%

PFB01: 2,10 24 to 240 VAC ± 15%
Dielectric voltage
Supply to output 4 kV
Rated operational power 4 W

Adjust the system frequency
setting DIP switch 3 and
select the desired function
setting the DIP switches 1, 2
and 4 as shown on the right.
To access the DIP switches
open the grey plastic cover
as shown on the right.

Selection of level and time
delay:

Upper knob:
Setting of upper level:

-10 to +100% of the range.

Centre knob:
Setting of lower level:

-100 to +10% of the range.

Lower knob:
Setting of delay on alarm
time: 0.1 to 30 s.

Function/Range/Level and Time Delay Setting

Setpoint range

ON: 2 Hz
OFF: 10 Hz

Relay working mode

ON: Normally De-Energized
OFF: Normally Energized

Contact input

ON: Lacth function enable
OFF: Inhibit function enable

System frequency

ON: 60 Hz
OFF: 50 Hz