Freqently Asked Questions

Here are the top 21 Frequently Asked Questions

How does it detect import and export conditions?

The Micro-Generation Power Manager™ is supplied with a sensor clamp, which is clipped around the incoming electrical supply to the building. The signal from this clamp is digitised and analysed by the Micro-Generation Power Manager™ and the amount of available ‘free’ export power is determined.

How does it control the power to the immersion heater?

The power to the immersion heater is controlled in 1% steps, from 1 to 100%. This is achieved by controlling the energy cycles being supplied to the immersion heater.

What is the minimum amount of export required for the Micro-Generation Power Manager™ to start heating the water?

The Micro-Generation Power Manager™ will wait for around 130W of export before any power is delivered to the immersion heater, once the water heating begins, however, the unit will be able control power in 1% steps, so for a 3kW heating element, the minimum power output is about 30W.

What is the payback period?

The payback period is dependant on a number of factors, the main ones being; daily hot water demand, hot water cylinder capacity, PV system size, the fuel currently used to heat the water and of course the cost of installation.

Here are some examples of expected payback periods:

A 3 person household with an oil boiler, a 150ltr hot water cylinder and a 3.68kW p PV system would have a payback period of approximately 2.5 years.
A 2 person household with a gas boiler, a 100ltr hot water cylinder and a 3.68kWp PV system would have a payback period of approximately 6.7 years.
A 4 person household using gas with a 200ltr cylinder and a 4kWp PV array would typically be looking at 5.5 years payback.
For a 2 person household with a 2.9kWp PV array, using electric to heat a 120ltr hot water cylinder a payback of 2.5 years is expected.

Do I need to fit anything else?

No – everything required to make use of your surplus PV energy is included. The Micro-Generation Power Manager™ device and the sensor clamp are both supplied.

What is the warranty?

The Micro-Generation Power Manager™ is covered by a manufacturers 3-year warranty, download the instruction manual for the full warranty details.

Does it affect my FiT or Export payments?

No – the FiT tariff is paid on generated power and the export tariff is (in most cases) deemed rather than metered.

Does it make a noise?

No – the Micro-Generation Power Manager™ is silent in operation.

Do I need to change the immersion heater to a smaller power one?

No – the Micro-Generation Power Manager™ will automatically adjust the power to the heating element as the available free power alters.

How do several Micro-Generation Power Manager™ devices work together?

Up to 4 Micro-Generation Power Manager™ units can be linked together to enable control of more heating elements. Each unit can output a maximum of 3kW, therefore up to 12kW of surplus electricity can be utilised. The units are linked via the RS485 MODBUS interface.

What data is logged by the Micro-Generation Power Manager?

The Micro-Generation Power Manager™ logs savings data in kWhs. Daily and monthly savings are displayed as well as the total for the year and the total since installation.

What is the RS485 MODBUS port for?

The interface allows several Micro-Generation Power Manager™ devices to be connected together for controlling more heaters. Also future products will be coming along soon that will make use of the RS485 interface.

How long can the sensor clamp cable be?

The sensor clamp cable can be extended up to 50 metres, when extending the sensor, twisted pair data cable should be used.

What is the multi-function relay for?

The internal relay is in addition to the proportional power output. This relay can be configured to operate for one of several functions; two heater switch over control for when the first heater is up to temperature, timed for hot water boost via an external heat source such as a gas boiler, control of a de-stratification pump and other functions. See the installation manual for a detailed description of the relay functions.

How long will it take to heat my water?

This is dependant of the amount of available surplus generated power, typically of a sunny day the water will reach 60°C by midday and on cloudy days the water may reach 50°C by the end of the day.

Will the Micro-Generation Power Manager™ ever use power from the grid?

In normal operation the Micro-Generation Power Manager™ will not use power from the grid to heat the water. When the timed or manual hot water boost function is used, the Micro-Generation Power Manager™ will take power from the grid if not enough export power is available.

What are the dimensions of the Micro-Generation Power Manager?

Width: 150mm, Height: 140mm and Depth: 64mm

What is the maximum PV system size?

There is no real maximum PV array size. For larger PV systems (more than 4kW) you may wish to use several Micro-Generation Power Manager™ units to control up to four 3kW loads so that more of the export power is utilised.

Can the Micro-Generation Power Manager™ be used with wind turbines?

Yes the Micro-Generation Power Manager™ can be used with all types of grid-tied electric microgeneration systems.

On days when the water is not fully heated, can the Micro-Generation Power Manager™ ‘boost’ the water heating to reach 60°C?

Yes it certainly can, this can be done using the immersion heater or your existing boiler if the relay function is used.

The Micro-Generation Power Manager™ has a built-in timer that can be programmed to operate once or twice daily to boost the water temperature, also there is manual boost function.

Can the Micro-Generation Power Manager™ be used with other appliances other than an immersion heater?

The Micro-Generation Power Manager™ can be used with most heaters up to 3kW. Electric underfloor heating, night storage heaters and electric towel radiators are just some of the types of heater devices you can control with the Micro-Generation Power Manager.

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