Thermal Overload Relays
Thermal Overload Relays
The thermal overload relay is a thermal-type overload-protection
relay that takes advantage of the heating-bimetal-results-in-bending
property. Mounted on appropriate contactors, they provide overload
protection and phase-loss protection in order to prevent motors from
burning out. On a standalone basis, they can also be used as a
over-current relay. Kasuga thermal overload relays includes models
with 3 thermal elements, and models featuring Phase-Loss
HRD 010 D
Protection (2E), for your various motor-protecting needs.
HRD 018 D
Structure and Characteristics
Terminal on the power side
Current adjustment dial
・Overload protection can be ensured by just adjusting this
to the rated current of the motor. It is possible to adjust it
within plus or minus 20%, and it is set in the middle
before shipment.
Trip indication lever
・This lever falls right and disappears when tripped. Or if
you push down this lever down to the right with a small
screw driver, you can intentionally break and check the
circuit.
Terminal on the load side
・The HRE75 type and with lower numbers are terminals
with a wire-press.
It is possible to just insert the wire for connection
without a crimp contact.
Reset button
・This will reset and make ready for operation again.
Control circuit terminal
・This contact sets apart the electromagnetic contactors
when tripped, or gives warnings.
Automatic/Manual switch tab
・The automatic reset and manual reset can be selected
with this tab. When it is set to the automatic restoration
mode, the bimetal will cool off after tripped and bend
back, and automatically reset. It is in the manual reset
position before shipment.
Mounting bracket
・We have special brackets available in case the
electromagnetic switch is assembled with
electromagnetic contactors.
＊This is a photo of the HRE 35 DG. The structure and characteristics vary depending on the model.
Selection map
Standalone Type Mount Type
Standard Type
2Thermal Elements
3Thermal Elements
Phase-Loss Protection (2E) Featured
2Thermal Elements
3Thermal Elements
Phase-Loss Protection (2E) Featured
HRD010
HRD010B
−
−
HRD010D
−
−
HRD018
HRD018B
HRD018BF
−
HRD018D
HRD018DF
−
2A
0.5A
0.5A
0.3A
Manual
1.2VA
MUD5
MUF7
MUF10-4
MUF10-5
HMUF10
MUK12
Auxiliary Contact
Open-Circuit Thermal Current
Rated Operational 110V
Current (AC-15)
220V
440V
Resetting
Power Consumption (per thermal element)
Corresponding Contactors
to Mount
［ ］Models in square
brackets : Applicable in
combination with CT
4A
3A
2A
1A
Manual
1.2VA
MUF18
HMU18
MUF20
［MUF300］
［MUF400］
7 to
10 to
12 to
18 to
24 to
9
12
15
22
30
to 11＊
to 14＊
to 18＊
to 26
to 36
4A
3A
2A
1A
Automatic-Manual
3.2VA
MUF25
MUF35
HRE150
−
−
−
HRE150DG
HRE150DF
HRE150DE
HRE180
−
−
−
HRE180DG
HRE180DF
HRE180DE
12 to 15 to 18＊
18 to 22 to 26＊
24 to 30 to 36＊
34 to 42 to 50
45 to 56 to 67
54 to 67 to 80
34 to 42 to 50＊
45 to 56 to 67＊
54 to 67 to 80＊
65 to 80 to 95
90 to 110 to 130
65 to 80 to 95＊
90 to 110 to 130＊
105 to 130 to 155
125 to 155 to 185
4A
3A
2A
1A
Automatic-Manual
4.2VA
MUF50
MUF65
MUE80
4A
3A
2A
1A
Automatic-Manual
4.8VA
MUE100
MUE125
4A
3A
2A
1A
Automatic-Manual
5.5VA
MUE150
MUE180
Auxiliary Contact Units・
Applications
Safety Covers
0.24 to 0.32 to 0.4＊ 0.24 to 0.32 to 0.4＊
0.5 to 0.6 to 0.7
0.5 to 0.6 to 0.7
1.0 to 1.2 to 1.4
1 to 1.2 to 1.4
1.4 to 1.7 to 2＊
1.4 to 1.7 to 2＊
1.7 to 2.2 to 2.7
1.7 to 2.2 to 2.7
2.4 to 3 to 3.6＊ 2.4 to 3 to 3.6＊
2.9 to 3.6 to 4.3
2.9 to 3.6 to 4.3
4 to 5 to 6
4 to 5 to 6
5.4 to 6.7 to 8
5.4 to 6.7 to 8
7 to 9 to 11
7 to 9 to 11
10 to 12 to 14
10 to 12 to 14
12 to 15 to 18
16 to 20 to 24＊
HRE75
−
−
−
HRE75DG
HRE75DF
HRE75DE
Industrial
Relays
Adjustable Current Range
(Rated)
Minimum−Median−Maximum
＊Production on Order
HRE35
−
−
−
HRE35DG
HRE35DF
HRE35DE
Star Delta
Automatic Starters
Frame
Reversible Electromagnetic Switches/ Contactors・
Electromagnetic Switches with ON-OFF Push-buttons・
Electromagnetic Swithes with Special Enclosures
・The mount type has a terminal plate that can be directly
installed onto electromagnetic contactors. The
standalone type has the dedicated connection band that
makes for easy connection to the electromagnetic
contactors.
Line-up Electromagnetic Electromagnetic Thermal Overload
Switches
Contactors
Relays
Thermal Overload Relays
30
Thermal Overload Relays
Line-up Electromagnetic Electromagnetic Thermal Overload
Switches
Contactors
Relays
Thermal Overload Relays (2 elements)
Mounting
Direct
mount
type
Rated current center
value(A)
Reversible Electromagnetic Switches/ Contactors・
Electromagnetic Switches with ON-OFF Push-buttons・
Electromagnetic Swithes with Special Enclosures
0.6
1.2
1.7
2.2
3
3.6
5
6.7
9
12
1.2
1.7
2.2
3
3.6
5
6.7
9
12
15
Type name
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
HRD
010
010
010
010
010
010
010
010
010
010
018
018
018
018
018
018
018
018
018
018
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
0006
0012
0017
0022
0030
0036
0050
0067
0090
0120
0012
0017
0022
0030
0036
0050
0067
0090
0120
0150
General mass
(kg)
0.07
0.11
Independent
type
Rated current center
value(A)
0.6 - 12
1.2 - 15
9
12
15
22
30
15
22
30
42
56
67
42
56
67
80
110
80
110
130
155
Type name
HRD 010
HRD 018
HRE 35
HRE 35
HRE 35
HRE 35
HRE 35
HRE 75
HRE 75
HRE 75
HRE 75
HRE 75
HRE 75
HRE 150
HRE 150
HRE 150
HRE 150
HRE 150
HRE 180
HRE 180
HRE 180
HRE 180
D
D
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
DG
□
□
0090
0120
0150
0220
0300
0150
0220
0300
0420
0560
0670
0420
0560
0670
0800
1100
0800
1100
1300
1550
General mass
(kg)
0.12
0.18
0.17
0.33
0.55
0.76
Remarks :
1. Put the rated capacity symbol in the square of the type name column.
2. Output contacts are 1c for HRD and HRE series and 1NO+1NC for HRG series.
Star Delta
Automatic Starters
HRD 010 B
HRE 35 DG
HRE 150 DG
Thermal Overload Relays (3 elements with open phase protector (2E))
3 elements
Industrial
Relays
Auxiliary Contact Units・
Applications
Safety Covers
31
Mounting
Mounting
Direct
mount
type
Independent
type
Rated current center
value(A)
With open phase protector (2E)
Type name
General mass
(kg)
Mounting
Direct
mount
type
1.2 - 15
HRD 018 BF □
0.11
1.2 - 15
9 - 30
15 - 67
42 - 110
80 - 155
HRD 018
HRE 35
HRE 75
HRE 150
HRE 180
0.18
0.17
0.33
0.55
0.76
DF
DF
DF
DF
DF
□
□
□
□
□
Independent
type
Remarks :
1. Put the rated capacity symbol in the square of the type name column.
2. Output contacts are 1c for HRD and HRE series and 1NO+1NC for HRG series.
Rated current center
value(A)
Type name
−
−
9 - 30
15 - 67
42 - 110
80 - 155
HRE
HRE
HRE
HRE
General mass
(kg)
−
35
75
150
180
DE
DE
DE
DE
□
□
□
□
0.17
0.33
0.55
0.76
Thermal Overload Relays
Accessories
Thermal
Overload Relays
HRD 010B
HRD 018B
HRD 018D
Mounting
bracket
−
HREK 10 A
HREK 10 B
HRDK 10 C
HREK 18 A
HRDK 18 B
HREK 20 A
−
Applicable
electromagnetic contactor
Thermal
Overload Relays
MUD 5
MUF 7, 10-4, 10-5
HMUF 10
MUK 12
MUF 18
HMU 18
MUF 20
MUF 300, 400
HRF 18 D
HRE 35 D
HRE 75 D
HRE 150 D
HRE 180 D
Mounting
bracket
−
HREK 35
HREK 75 A
HREK 75 B
HREK 150
HREK 180
HREK 180
Connecting
band
−
HREJ 35
HREJ 50
HREJ 80
HREJ 100
HREJ 180
HREJ 180
Applicable
electromagnetic contactor
MUF 300, 400
MUF 25, 35
MUF 50, 65
MUE 80
MUE 100
MUE 125, 150
MUE 180
Remark : Contact us for fitting and connecting band.
Application and selection to motor protection
Frame
HRD010
HRD018
HRE35
HRE75
HRE150
HRE180
HRD018
(With CT)
The performance characteristics of the thermal relay comply with the Electrical Appliance and Material Safety Law.
● Cold start: This applies to the time when the motor starts under the condition that the thermal relay receives an
overload current when it is not under the influence of current-oriented heat.
● Hot start: This applies to the time when the motor starts or restarts under the condition that the thermal relay receives
an overload current when the rated current runs with a constant temperature rise.
Auxiliary Contact Units・
Applications
Safety Covers
● Ones with an applicable motor capacity indicated must comply with the below when the ambient temperature is
40˚C plus or minus 2˚C.
（1）When the electric current equivalent to 500% of the rated current of the over-current trip equipment runs, it must
open circuit in more than 3 seconds and less than 45 seconds.
（2）After the electric current equivalent to the rated current of the over-current trip equipment flows until the
temperature rise in each part are almost constant, and when the electric current equivalent to 200% of the
rated current of the over-current trip equipment is run, it must open circuit in less than 4 minutes.
（3）After the electric current equivalent to the rated current of the over-current trip equipment flows until the
temperature rise in each part are almost constant, and when the electric current equivalent to 125% of the rated
current of the over-current trip equipment is run, it must open circuit in less than 60 minutes.
Industrial
Relays
Performance Characteristics
Star Delta
Automatic Starters
Rated current
Adjusting range(A)
Heat name
0.5 to 0.6 to 0.7
0006
1 to 1.2 to 1.4
0012
1.4 to 1.7 to 2
0017
1.7 to 2.2 to 2.7
0022
2.4 to 3 to 3.6
0030
2.9 to 3.6 to 4.3
0036
4 to 5 to 6
0050
5.4 to 6.7 to 8
0067
7 to 9 to 11
0090
10 to 12 to 14
0120
12 to 15 to 18
0150
18 to 22 to 26
0220
24 to 30 to 36
0300
34 to 42 to 50
0420
45 to 56 to 67
0560
54 to 67 to 80
0670
65 to 80 to 95
0800
90 to 110 to 130
1100
105 to 130 to 155
1300
125 to 155 to 185
1550
2.25 to 3 to 3.75
003T
(CT400/5)
3 to 4 to 5
004T
(CT400/5)
Reversible Electromagnetic Switches/ Contactors・
Electromagnetic Switches with ON-OFF Push-buttons・
Electromagnetic Swithes with Special Enclosures
Applicable motor capacity(kW)
3φ 220V
3φ 440V
1φ 110V
1φ 220V
0.1
0.2
−
−
0.2
0.4
−
−
−
0.75
−
−
0.4
−
−
−
−
−
−
−
0.75
1.5
−
−
1.1
2.2
0.2
0.4
−
−
1.5
3.7
0.4
0.75
2.2
−
−
−
2.7
5.5
0.75
1.5
3.7
7.5
1.1
−
5.5
11
1.5
−
7.5
15
−
−
11
22
−
−
15
30
−
−
19
37
−
−
22
45
−
−
30
55
−
−
37
75
−
−
45
90
−
−
55
110
−
−
75
150
−
−
90
180
−
−
110
200
Line-up Electromagnetic Electromagnetic Thermal Overload
Switches
Contactors
Relays
Thermal Overload Relays
32
Thermal Overload Relays
Line-up Electromagnetic Electromagnetic Thermal Overload
Switches
Contactors
Relays
Thermal Overload Relays
Dimensions (Unit : mm)
HRD 010
●
HRD010B（Direct type）
Reversible Electromagnetic Switches/ Contactors・
Electromagnetic Switches with ON-OFF Push-buttons・
Electromagnetic Swithes with Special Enclosures
HRD010D（Independent type）
IEC 35mm
IEC Rail
Main Terminal
Conditions)
(Main Terminal Position)
Auxiliary Terminal
(Main Terminal Position)
Hole Pitches
(In Case with a 7.5mmHeight Rail Mounted)
Main Terminal
(Main Terminal Position)
Conditions)
General mass：0.07kg
General mass：0.12kg
HRD 018
●
HRD018B（Direct type）
●
HRD018D（Independent type）
Terminal
Conditions)
31
32
31
Auxiliary
Terminal
Terminal
Conditions)
(Main Terminal Position)
33
32
33
(Main Terminal Position)
Star Delta
Automatic Starters
Industrial
Relays
Auxiliary Contact Units・
Applications
Safety Covers
33
●
Hole Pitches
(Main Terminal Position)
General mass：0.11kg
General mass：0.18kg
HRE 35
●
HRE35D□
(Manual Reset)
(Automatic Reset)
(Main Terminal Position)
Main Terminal
Auxiliary Terminal
(Main Terminal Position)
Hole Pitches
General mass：0.17kg
Thermal Overload Relays
HRE 75
● HRE75D□
(Manual Reset)
(Automatic Reset)
(Main Terminal Position)
Main Terminal
Auxiliary Terminal
(Main Terminal Position)
Hole Pitches
General mass：0.33kg
Reversible Electromagnetic Switches/ Contactors・
Electromagnetic Switches with ON-OFF Push-buttons・
Electromagnetic Swithes with Special Enclosures
HRE 150
●
HRE150D□
(Main Terminal Position)
(Manual Reset)
(Automatic Reset)
Hole Pitches
Auxiliary Terminal
(Main Terminal Position)
General mass：0.55kg
Industrial
Relays
HRE 180
●
Star Delta
Automatic Starters
Main Terminal
Line-up Electromagnetic Electromagnetic Thermal Overload
Switches
Contactors
Relays
Thermal Overload Relays
HRE180D□
(Manual Reset)
Terminal
(Automatic Reset)
Position)
Auxiliary Terminal
Hole Pitches
Main Terminal M1 (Load Position)
(Main Terminal Position)
General mass：0.76kg
Auxiliary Contact Units・
Applications
Safety Covers
(Main Terminal Position)
34
Thermal Overload Relays
Line-up Electromagnetic Electromagnetic Thermal Overload
Switches
Contactors
Relays
Reversible Electromagnetic Switches/ Contactors・
Electromagnetic Switches with ON-OFF Push-buttons・
Electromagnetic Swithes with Special Enclosures
Star Delta
Automatic Starters
Industrial
Relays
Auxiliary Contact Units・
Applications
Safety Covers
35
Thermal Overload Relays
Internal connection diagram
HRD 010
With 2
Thermal Elements
(Standard)
Notes :
1. This model cannot obtain With 3 Thermal
Elements and Phase-Loss Protection.
2. Automatic reset system is not featured in this
model.
3. Terminal 8 is not included as standard.
HRD 018
With 2
Thermal Elements
(Standard)
Notes :
1. This model cannot obtain Phase-Loss
Protection.
2. Automatic reset system is not featured in this
model.
3. Terminal 8 is not included as standard.
With 3
Thermal Elements
HRE 35, HRE75, HRE150, HRE180
With 2
Thermal Elements
(Standard)
With 3
Thermal Elements,
Phase-Loss
Protection Featured