How to set up an MC250 Safety These instructions are interim until the new 2014 Technical Manual is written and issued. These notes are intended to guide qualified technicians in the setup of diversion loads with the following turbine types:  PowerSpout PLT/TRG 40, 80, 80C, 100C, 170C, 200C  PowerSpout LH150, LH250 and LH Pro The “C” denotes a “Klampit” is fitted in the hydro product, a “Klampit” will crowbar the PMA at a set voltage of 75,120, 140 and 240 VDC as appropriate to the application. 120 VDC Klampit (ELV) is installed for AUS/NZ and a 140VDC Klampit to all other markets unless otherwise requested. Most clients will order:  For an MC250 PLT/TRG 80, 200C or LH250  For an MC200 PLT/TRG 170C or LH150  For an MC150 PLT/TRG 40, 100C or LH150 Please ensure you abide by all the safety warnings in the 2014 Installation Manual that you must read in conjunction with this document. Fuses/breakers are not shown for clarity. This information is already covered in the new 2014 Installation Manual. Introduction The Midnite Classic 150, 200 and 250 is a product range packed with advanced features, it is far more complicated to use and understand than the more recent Midnite KID product. The supporting manual is poor and often does not fully described many of the more advanced features fully. Some options listed in the manual are not contained in the display options on the device and vice-versa. This can make for a very confusing experience when trying to program advance AUX relay functions with this controller. You have been warned, we hope these notes make it a little easier for you. If you can use a Classic KID do so. You are likely to require the Midnite Classic 150,200 and 250 if you need over a 150V rating or more than 30 amp of output to the battery bank. This document looks only at how to set up PowerSpout hydro turbines with either input or output diversion control. This document covers only a few of the features, primarily ones that have been shown to work well with PowerSpout hydro products. How to connect the MC to the battery, turbine, AUX1, AUX2 and AUX1 jumper settings. Note: you need to connect the fine red and black wire to the AUX2 position (AUX1 is shown wired in this picture) AUX2 wiring will look like this Simple Wiring Diagram (output side diversion): Simple diagram Full diagram with grounded battery Full diagram with ungrounded battery Simple Wiring Diagram (input side diversion): Simple diagram Full diagram with grounded battery Full diagram with ungrounded battery Set INTERVAL TWIDDLE DITHER in HYDRO mode – how the regulator tracks for maximum power point Press main menu key. Select mode with < > arrow keys as per first picture above. Select HYDRO function and turn ON as per middle picture. Press very top right hand key. Press the down arrow key until you get INTERVAL TWIDDLE DITHER as shown, the only other option is MANUAL MPP V. INTERVAL TWIDDLE DITHER sweeps up and down continuously. TWIDDLE DITHER only uses the DEPTH to determine how far it sweeps away from the MPP voltage last found. This Twiddle Dither option works well with hydro. In TWIDDLE DITHER mode, the MPP V setting does not actually do anything, so leave it set at 100 MPP V and Min V set at 10. Depth in the range 1-3% is OK. Only the DEPTH setting actually does anything. Yes it can be confusing - sorry we did not right this software. Twiddle Dither is a fast tracking mode for hydro, it is constantly moving as fast as it can go, by the amount that the Sweep DEPTH is set for. HYDRO mode when sweeping up (in voltage to find max power point), goes slower so that the turbine is not immediately unloaded, giving false high output power from the turbine inertia. Once all set as per the images above remember to press Enter to save the changes. At this stage we have only set how the Midnite Classic will track the hydro turbine, next we need to set how the Midnite Classic will divert surplus power not required to charge the batteries. With diversion of surplus power we have a few options. At this point we tested a 60dc-1s-12p-Star HP PMA at 1200rpm, the result is opposite. At 1200 rpm the PMA in Twiddle Dither produced 1264W with a MPPV of about 66.8V. This is an excellent result. If you have purchased a PLT100C for example, the MPPV will be about 100V, not 66.8V as in this example. The MPP V and MIN V settings have no effect on this result. The DEPTH set to 1% works well and prevents excessive wander. If you set DEPTH to 10% then the Watts will wander more and you will spend more time away from the ideal MPP so harvest less total energy. Setting up diversion loads The Midnite Classic range has 2 AUX relays. We next consider how to set these up correctly to divert surplus power not needed (on either the input side or output side) to a resistive load. AUX Setting: To use an external load to divert surplus power, an external solid state relay (SSR) has to be used with the Midnite Classic. The smaller KID (made by the same company) does not require an external relay. This relay is shown in the simple wiring diagram above and can be supplied with your turbine order if required. The Midnite Classic has two auxiliary ports AUX1 and AUX2 which can be used to control diversion loads. In this document we only consider AUX2 as this can produce a PWM signal to drive the SSR at high frequency. AUX2: IN/OUT → 0V to 12V or 12V to 0V signal (PWM at hundreds Hz rate, suitable for SSRs) We recommend you use AUX2 and the following options:    WASTE NOT HI – to PWM the SSR relative to battery charge state voltage Pv V ON HIGH - to PWM the SSR based on the incoming voltage CLIPPER CONTROL - to PWM the SSR based on the incoming voltage WASTE NOT HI – setting example This option can be used to divert surplus power on the output side of the regulator only. Set up AUX2 to WASTE NOT HI (note this is called OPPORTUNITY HIGH in the user manual). In the example the -0.2 VOLTS means start PWM of the AUX relay when you get within 0.2 V of the bulk, float or EQ settings. VOLT setting will normally be in the range -0.5-0.0 volts. Always leave WIDTH at 1.0V as this is the lowest value allowed. Repeating the test at 1200 rpm, we observed 1258W, AUX2 ON diverting power from the battery side to a diversion load. This worked well. The battery bulk setting was 57.0V Pv V ON HIGH – setting example This option can be used to divert surplus power on the input or output side of the regulator. Set up AUX2 as shown. From the previous tests the MPPV (in this example) <70 V, so we have set VOLTS to 75. This may reduce the generation Watts a little. The diversion load has been connected via the SSR to the battery side of the system. This worked very well with 1149W generated, lowering the 75 to 70 would improve the generation Watts. The above test was repeated but the diversion load connected via the SSR to the input side of the regulator. In this case the diversion loads was a standard 120V 1500W water element. The result appears very different. This time we generate 326W on the display, but we also measured 8.4A at 81.4V going to the resistive element = 684W. Total generation = 326 + 684 = 1010W. Before we observed 1149W, the reduction is due to the resistive element not being large enough (at this voltage), which results in the MPPV being a little too high at 81.4V. From the table opposite, for 684W of diversion load we need a voltage above 80. Fitting a larger 120V 2000W element would give a much better result, as would fitting a PMA with a higher MPPV. Voltage 120 Volt step 10 20 30 40 50 60 70 80 90 100 110 120 Watts 1500 Watts 10 42 94 167 260 375 510 667 844 1042 1260 1500 CLIPPER CONTROL – setting example This option can be used to divert surplus power on the input or output side of the regulator. It is very similar to the previous Pv V ON HIGH example. This worked very well with 1152W generated as shown. The above test was repeated but the diversion load connected via the SSR to the input side of the regulator. In this case the diversion loads was a standard 120V 1500W water element. The result appears very different. This time we generated 417W on the display, but we also measured 8.4A at 79.4V going to the resistive element = 667W. Total generation = 417 + 667 = 1084W. Before we observed 1152W. This reduction is due to the resistive element not being large enough (at this voltage), which results in the MPPV being a little too high at 79.4V. Fitting a larger 120V 2000W element would give a much better result, as would fitting a PMA with a higher MPPV. Typical initial settings If you have a:  PLT/TRG 40 set VOLTS to 50V and WIDTH to 1.0V - (MC150 used)  PLT/TRG 80C set VOLTS to 80V and WIDTH to 1.0V - (MC150 used)  PLT/TRG 100C set VOLTS to 100V and WIDTH to 1.0V - (MC150 used)  PLT/TRG 170C set VOLTS to 170V and WIDTH to 1.0V - (MC200 used)  PLT/TRG 200C set VOLTS to 200V and WIDTH to 1.0V - (MC250 used)  PLT/TRG 80 set VOLTS to 80V and WIDTH to 1.0V - (MC250 used)  LH 150 set VOLTS to 100V and WIDTH to 1.0V - (MC150 used)  LH 250 set VOLTS to 200V and WIDTH to 1.0V - (MC250 used) Some adjustment may be required once you have the system running, these values are only an initial starting point. The way the AUX2 relay works is that user sets a desired threshold and a WIDTH voltage, this means that at the desired voltage (VOLTS), the AUX2 will start to PWM and it has to go above or below the width to completely change states (from 0V to 12V). This gives a smooth transition between the battery load and the resistive. The graph above describes the operation of Aux 2 Input side diversion 120/240V water element (common globally) can be used with Midnite Classic products. Elements typically used are indicated below:    Midnite Classic 150 – 120V 1000-2000W elements Midnite Classic 200 – suitable 120 or 240V elements Midnite Classic 250 – 240V 1000-3000W elements TWEAKS setting: You may need to turn off Arc Fault detection (this is really for solar PV input only, it may nuisance activate when used with hydro turbines). Ground Fault detection is often not required for hydro installation, refer to the PowerSpout install manual for more information. For an explanation of the other abbreviations, look in MC-Manual from page 6.