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1-pole impulse-driven latching relay for smart electricity meters and prepaid metering circuits: 100A resistive switching, 5-24 VDC coil, AgSnO2 contacts, fast connection terminals.


The GRT508HC is a 1-pole latching relay developed for smart electricity meters, prepaid meters and energy measurement modules. It switches resistive loads up to 100A at a maximum switching voltage of 440VAC / 28VDC with AgSnO2 contacts. The coil is driven by an impulse only: the relay changes state on the pulse and holds that state without continuous coil power, which keeps driver circuitry simple and standby consumption low. Coil voltage can be specified between 5 and 24 VDC, and both single-coil and double-coil excitation are supported. A 1500A / 10ms maximum short-circuit current rating and 4kV dielectric strength between coil and contacts address the fault-current and isolation requirements typical of metering designs. The relay is RoHS compliant and compliant with IEC62055-31 UC2, with an outline of 58 x 40 x 20.8 mm and fast connection installation.
Rated resistive load and maximum switching current both reach 100A, so one relay covers high-current meter circuits instead of paralleled switching devices.
Only an impulse is needed to change state, for both single and double coil versions - the contact position is maintained after the pulse ends.
A defined maximum short-circuit current of 1500A for 10ms gives designers a documented figure for fault-current coordination in meter boards.
Reinforced isolation between the control coil and the load contacts supports safe separation of metering electronics from mains switching.
The small outline and fast connection installation leave more room for current transformers, shunts and terminal blocks inside the meter housing.
Compliance with IEC62055-31 UC2 and RoHS helps meter makers address European and Indian market documentation requirements.
| Parameter | Value |
|---|---|
| Model | GRT508HC |
| Relay type | 1-pole latching relay |
| Rated load (resistive) | 100A |
| Max. switching current | 100A |
| Max. switching voltage | 440VAC / 28VDC |
| Contact material | AgSnO2 |
| Coil voltage | 5-24 VDC |
| Coil excitation | Impulse, single and double coil |
| Dielectric strength (coil to contacts) | 4kV |
| Max. short-circuit current | 1500A / 10ms |
| Mechanical endurance | 100,000 OPS |
| Electrical endurance | 6,000 OPS |
| Ambient temperature | -40C to +85C |
| Installation form | Fast connection |
| Outline dimensions | 58 x 40 x 20.8 mm |
| Compliance | RoHS; IEC62055-31 UC2 |
| Materials | Copper / plastic |
The contact set uses AgSnO2, a silver-tin-oxide material selected for resistive 100A switching duty. The relay body combines copper conductive parts and plastic housing material within the 58 x 40 x 20.8 mm outline. The magnetic latch holds the contact position mechanically after each impulse, so the drive circuit does not have to energise the coil for the whole time the meter is connected or disconnected. Endurance is specified at 100,000 mechanical operations and 6,000 electrical operations at the rated load.
The GRT508HC is intended for the smart metering industry: on-off control of energy meter circuits in smart electricity meters, prepaid meters and energy measurement modules, including smart home metering devices. Typical working conditions for these installations are an ambient temperature of -40C to +85C, relative humidity of 5% to 85% RH non-condensing, altitude up to 2000m, no corrosive gas or explosive dust in the surroundings, and resistive load. Requirements often driving the selection are high shock and vibration resistance, long mechanical life and low coil power consumption.
Custom latching relay assemblies can be supplied with flexible wire and/or copper straps, and/or with an integrated shunt, so the relay can be matched to a specific meter terminal layout. Because coil voltage, coil configuration and assembly format are project-specific, share your drawing, coil voltage and connection requirement with the sales team before ordering. Please confirm MOQ, lead time and sample availability with the supplier for your configuration.
Does the coil need continuous power to keep the relay latched?
No. The GRT508HC only needs an impulse excitation to change state, for both single-coil and double-coil versions. The contact position is maintained after the impulse ends, which is why coil power consumption stays low.
Which coil voltages are available?
Coil voltage can be selected within the 5-24 VDC range. State your driver supply voltage when requesting a quotation so the correct coil version can be confirmed.
What load can the contacts switch?
Rated load is 100A resistive with a maximum switching current of 100A and a maximum switching voltage of 440VAC / 28VDC. The specification refers to resistive load.
What is the short-circuit withstand of this relay?
The maximum short-circuit current is 1500A for 10ms, which can be used as the reference figure when coordinating fault current in the meter design.
Which standards and directives does it meet?
The GRT508HC is RoHS compliant and compliant with IEC62055-31 UC2. Dielectric strength between coil and contacts is 4kV.
Can the relay be supplied as a custom assembly?
Yes. Custom assemblies are available with flexible wire and/or copper straps, and/or with an integrated shunt. Provide your assembly drawing and connection requirement for evaluation.
What are the dimensions and installation form?
The outline is 58 x 40 x 20.8 mm and the installation form is fast connection. Operating ambient temperature range is -40C to +85C.
Send your coil voltage, single or double coil preference, assembly drawing and annual volume for a configuration-matched quotation.
Contact: Annie
Mobile / WhatsApp: +86 13626734569 | WhatsApp: +86 18057329886
Email: sales5@great-relay.com
Address: No.9 Linhu Avenue, Yaozhuang Town, Jiashan County, Jiaxing City, Zhejiang Province, China
Website: en.grtrelay.com
grt508hc-latching-relay-100a-front.png - Alt: GRT508HC 100A latching relay front view with fast connection terminals
grt508hc-latching-relay-100a-profile.png - Alt: Side view of GRT508HC smart meter latching relay, 58 x 40 x 20.8 mm body