Maximize Switch Capacity. Minimize Power Consumption.

Panasonic's HE Relays PV Type are available in multiple different contact ratings: 35A, 48A, 90A, and New 90A Wide Gap!

These Relays have a 1 Form A (SPST-NO) contact arrangement in a PC Board mountable small case size.  HE Relays PV Type features the minimum contact gap and 2.5kW surge breakdown required by photovoltaic standard requirements. These Relays contribute to overall energy savings with low coil holding voltage that can be reduced down to just 40% of the nominal coil voltage.  These Relays provide the necessary high switching capacity and low power consumption required by energy management applications.

Features of the HE Relay PV Type

  • High Capacity Contact Rating: 35A, 48A, or 90A types
  • Compact Case Size: 35A/48A - 33 x 38 x 36.3H mm, 90A - 33 x 38 x 38.8H mm
  • PCB Mounted
  • Low Coil Holding Power
  • Large Contact Gap: 35A/48A - 2.5 mm, 90A - 3.0 mm
  • High Surge Breakdown Voltage: 2.5kW
  • RoHS/REACH Compliant

Benefits of the HE Relay PV Type

  • High-Capacity Control
  • Takes Up Less Board Space
  • Easier Assembly For High-Volume Projects
  • Low Power Operation
  • Meets VDE0126 and EN61810-1
  • Environmentally Friendly
Series image for HE Series Relays PV Type

HE Series Relays PV Type

Part number list

Results 16
Models table for series HE Series Relays PV Type
Part No.DatasheetContact GapRated Coil VoltageContact ArrangementMax. Switching CurrentProtective ConstructionOperating Function Terminal TypeContact TypePacking Quantity; Inner Carton (Pcs.) Packing Quantity; Outer Carton (Pcs.)Operate Voltage (@20oC)Release Voltage (at20°C) Rated Operating Current [±10%] (at 20°C)Resistance [±10%] (at 20°C) Rated Operating Power Max. Allowable Voltage (at 20°C 68°F)Contact ShapeContact Resistance (Initial)Contact MaterialContact Rating (Resistive Load)Max. Switching Power (Resistive Load) Max. Switching VoltageMin. Switching Load (Reference Value) Insulation Resistance (Initial)Dielectric Strength (Initial): Between Contact and CoilDielectric Strength (Initial): Between Open ContactsSurge Withstand Voltage (Initial): Between Contact and CoilCoil Holding VoltageOperate Time (Initial) (At 20oC)Release Time (Initial) (at 20°C) Hock Resistance (Functional)Hock Resistance (Destructive)Vibration Resistance (Functional) Vibration Resistance (Destructive)Mechanical LifeConditionsWeight (Typ.)Resistive LoadPacking QuantityInductive Load
2.5mm
24 V DC
1 Form A
48 A (AC, DC)
Flux-resistant
Single side stable
PC board terminal (blade)
48 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
80 mA
300 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 100 mΩ (by voltage drop 6 V DC 1 A)
AgNi type
48 A 490 V AC, 48 A 48 V DC
23,520 VA (AC), 2,304 W (DC)
490 V AC, 48 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 10x106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 80 g
[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 30x103 ope. 48 A 277 V AC
Min. 30x103 ope. 48 A 30 V DC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 48 A 490 V AC
Min. 10x103 ope. 48 A 48 V DC
Carton
[at 85℃, switching frequency ON : OFF = 0.1 s : 10 s]
Min. 30x103 ope. 48 A 250 V AC (cosΦ = 0.8)
Min. 50 ope. 72 A 250 V AC (cosΦ = 0.8)
2.5mm
6 V DC
1 Form A
48 A (AC, DC)
Flux-resistant
Single side stable
PC board terminal (blade)
48 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
320 mA
18.8 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 100 mΩ (by voltage drop 6 V DC 1 A)
AgNi type
48 A 490 V AC, 48 A 48 V DC
23,520 VA (AC), 2,304 W (DC)
490 V AC, 48 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 10x106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 80 g
[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 30x103 ope. 48 A 277 V AC
Min. 30x103 ope. 48 A 30 V DC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 48 A 490 V AC
Min. 10x103 ope. 48 A 48 V DC
Carton
[at 85℃, switching frequency ON : OFF = 0.1 s : 10 s]
Min. 30x103 ope. 48 A 250 V AC (cosΦ = 0.8)
Min. 50 ope. 72 A 250 V AC (cosΦ = 0.8)
3.0mm
24 V DC
1 Form A
60 A (AC), 90 A (DC)
Flux-resistant
Single side stable
PC board terminal (wide blade)
90 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
80 mA
300 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 10 mΩ (by voltage drop 5 V DC 20 A)
Max. 3 mΩ (by voltage drop 5 V DC 90 A, reference value)
AgNi type
60 A 490 V AC, 90 A 60 V DC
29,400 VA (AC), 5,400 W (DC)
490 V AC, 60 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 85 g
[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 60 A 277 V AC
Min. 103 ope. 90 A 277 V AC
Min. 103 ope. 90 A 60 V DC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 60 A 490 V AC
Min. 10x103 ope. 80 A 277 V AC
Min. 10x103 ope. 80 A 48 V DC
Carton
2.5mm
9 V DC
1 Form A
35 A (AC, DC)
Flux-resistant
Single side stable
PC board terminal
35 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
213 mA
42.2 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 100 mΩ (by voltage drop 6 V DC 1 A)
AgSnO2 type
35 A 490 V AC, 35 A 48 V DC
17,150 VA (AC), 1,680 W (DC)
490 V AC, 48 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 10x106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 80 g
[room temperature, switching frequency: 20 times/min]
Min. 200x103 ope. 30 A 250 V AC

[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 30x103 ope. 35 A 277 V AC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 35 A 490 V AC
Min. 10x103 ope. 35 A 48 V DC
Carton
3.6mm
24 V DC
1 Form A
55 A (AC), 90 A (DC)
Flux-resistant
Single side stable
PC board terminal (wide blade)
90 A Wide gap
25
100
Max. 75% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
80 mA
300 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 10 mΩ (by voltage drop 5 V DC 20 A)
Max. 3 mΩ (by voltage drop 5 V DC 90 A, reference value)
AgNi type
55 A 800 V AC, 90 A 60 V DC
44,000 VA (AC), 5,400 W (DC)
800 V AC, 60 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 85 g
[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 60 A 277 V AC
Min. 103 ope. 90 A 277 V AC
Min. 103 ope. 90 A 60 V DC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 103 ope. 55 A 800 V AC
Min. 10x103 ope. 60 A 490 V AC
Min. 10x103 ope. 80 A 277 V AC
Min. 10x103 ope. 80 A 48 V DC
Carton
3.0mm
12 V DC
1 Form A
60 A (AC), 90 A (DC)
Flux-resistant
Single side stable
PC board terminal (wide blade)
90 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
160 mA
75 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 10 mΩ (by voltage drop 5 V DC 20 A)
Max. 3 mΩ (by voltage drop 5 V DC 90 A, reference value)
AgNi type
60 A 490 V AC, 90 A 60 V DC
29,400 VA (AC), 5,400 W (DC)
490 V AC, 60 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 85 g
[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 60 A 277 V AC
Min. 103 ope. 90 A 277 V AC
Min. 103 ope. 90 A 60 V DC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 60 A 490 V AC
Min. 10x103 ope. 80 A 277 V AC
Min. 10x103 ope. 80 A 48 V DC
Carton
3.0mm
6 V DC
1 Form A
60 A (AC), 90 A (DC)
Flux-resistant
Single side stable
PC board terminal (wide blade)
90 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
320 mA
18.8 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 10 mΩ (by voltage drop 5 V DC 20 A)
Max. 3 mΩ (by voltage drop 5 V DC 90 A, reference value)
AgNi type
60 A 490 V AC, 90 A 60 V DC
29,400 VA (AC), 5,400 W (DC)
490 V AC, 60 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 85 g
[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 60 A 277 V AC
Min. 103 ope. 90 A 277 V AC
Min. 103 ope. 90 A 60 V DC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 60 A 490 V AC
Min. 10x103 ope. 80 A 277 V AC
Min. 10x103 ope. 80 A 48 V DC
Carton
2.5mm
9 V DC
1 Form A
48 A (AC, DC)
Flux-resistant
Single side stable
PC board terminal (blade)
48 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
213 mA
42.2 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 100 mΩ (by voltage drop 6 V DC 1 A)
AgNi type
48 A 490 V AC, 48 A 48 V DC
23,520 VA (AC), 2,304 W (DC)
490 V AC, 48 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 10x106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 80 g
[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 30x103 ope. 48 A 277 V AC
Min. 30x103 ope. 48 A 30 V DC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 48 A 490 V AC
Min. 10x103 ope. 48 A 48 V DC
Carton
[at 85℃, switching frequency ON : OFF = 0.1 s : 10 s]
Min. 30x103 ope. 48 A 250 V AC (cosΦ = 0.8)
Min. 50 ope. 72 A 250 V AC (cosΦ = 0.8)
2.5mm
12 V DC
1 Form A
35 A (AC, DC)
Flux-resistant
Single side stable
PC board terminal
35 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
160 mA
75 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 100 mΩ (by voltage drop 6 V DC 1 A)
AgSnO2 type
35 A 490 V AC, 35 A 48 V DC
17,150 VA (AC), 1,680 W (DC)
490 V AC, 48 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 10x106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 80 g
[room temperature, switching frequency: 20 times/min]
Min. 200x103 ope. 30 A 250 V AC

[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 30x103 ope. 35 A 277 V AC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 35 A 490 V AC
Min. 10x103 ope. 35 A 48 V DC
Carton
2.5mm
24 V DC
1 Form A
35 A (AC, DC)
Flux-resistant
Single side stable
PC board terminal
35 A
25
100
Max. 70% V of rated coil voltage (Initial)
Min. 10% V of rated coil voltage (Initial)
80 mA
300 Ω
1,920 mW
110% V of rated coil voltage
Single
Max. 100 mΩ (by voltage drop 6 V DC 1 A)
AgSnO2 type
35 A 490 V AC, 35 A 48 V DC
17,150 VA (AC), 1,680 W (DC)
490 V AC, 48 V DC
100 mA 5 V DC
Min. 1,000 MΩ (at 500 V DC, Measured portion is the same as the case of dielectric strength.)
5,000 Vrms for 1 min (detection current: 10 mA)
2,000 Vrms for 1 min (detection current: 10 mA)
10,000 V
40 to 100% V (at -50~55℃)
50 to 60% V (at 55~85℃)
Max. 30 ms at rated coil voltage (without bounce)
Max. 10 ms at rated coil voltage (without bounce, without diode)
98 m/s2 (half-sine shock pulse: 11 ms, detection time: 10 μs)
980 m/s2 (half-sine shock pulse: 6 ms)
10 to 55 Hz (at double amplitude of 1 mm, detection time: 10 μs)
10 to 55 Hz (at double amplitude of 1.5 mm)
Min. 10x106 ope. (switching frequency: at 180 times/min)
Ambient temperature: -50 to +85℃
(When using at 55℃ or higher, the coil holding voltage should be 50% V to 60% V)
Humidity: 5 to 85% RH (Avoid icing and condensation)
Approx. 80 g
[room temperature, switching frequency: 20 times/min]
Min. 200x103 ope. 30 A 250 V AC

[at 85℃, switching frequency ON : OFF = 1 s : 9 s]
Min. 30x103 ope. 35 A 277 V AC

[room temperature, switching frequency ON : OFF = 1 s : 9 s]
Min. 10x103 ope. 35 A 490 V AC
Min. 10x103 ope. 35 A 48 V DC
Carton

Solar Storage Solutions

solar-storage-solutions-413x233
Solutions to Help Reduce Energy Consumption

In today’s environmentally conscious world, Solar Storage is an increasingly popular system that captures energy and stores it to perform operations in the future. These Systems involve converting many forms of energy, such as electrical potential energy or kinetic energy, into more economically storable formats for short-term and long-term use. Panasonic product solutions include Relays, Passive Components, such as Capacitors, Metal Oxide Varistors, and more. 

New Product Information Download

NPI Download Item list layout
Stay Up-To-Date On The Latest Product Details

Find the latest new product details here, with a convenient PDF product summary document. Quickly access and download the latest product information for the new HE Series Relays PV Type, including product specifications, features, benefits, industries and applications, software, block diagrams, and technical characteristics.  

Latest Videos

Playlist

Thumbnail for Smart Grid Products: LF-G Series Power Relays

Smart Grid Products: LF-G Series Power Relays

Thumbnail for Smart Grid Products: HE-V Series Power Relays

Smart Grid Products: HE-V Series Power Relays