Carl

Two Outback Charge Controllers for sale: SOLD Flexmax 60 Amp: R2500 Flexmax 80 Amp: R3000 Available in Cape Town, Plumstead. Can courier at buyers expense. Contact Carl for further information - 084 677 1883

Set of 16 Trojan T105 for Sale: SOLD Batteries 3 years old. Includes Cabling. Includes Battery Isolation Busbar Box. Batteries scrap value: R6000 Available in Cape Town, Plumstead. Asking Price: R13 500 Contact Carl - 084 677 1883 (Note: Two Outback Charge Controllers also available)

Price drop to R1500.

Kaco Powador 5500 Inverter for sale: 5500 Watts MPP range 350 - 600 Volts IP 54 Made in Germany Unit in excellent condition. Collection in Cape Town / or courier available for Purchaser expense. Contact Carl - 084 677 1883

Goodwe Hybrid Inverter For Sale. Battery Voltage: 48 Volts Max PV Power: 4600 Watts Battery Max Charge / Discharge Current: 50 Amps Backup Rated Power: 2300 VA IP 65

Huawei Sun 2000 - 20KTL: 3 MPPTs, 6 Strings IP 65 with Natural Cooling Surge Arresters on DC and AC side Huawei Smart Logger - 1000: Modbus - TCP for connections to Huawei NetEco 5 Months Warranty on both items. Collection in Cape Town or Courier available at additional cost.

Price Reduced to R165 000.

Thanks Charl, we have another leaf with 11 bars (150 KM range) which should be good for our driving requirements for at least another 6 years.

Current range that it charges to is between 55 - 65 KM. Range is calculated after every recharge and is based on previous trip conditions. The battery pack is a standard 24kWh pack and a new pack will give you 180 KM range in summer and around 160 KM in winter. That is for moderate driving. Our long term average for over 2 years of driving is 7.5 KM / KWh (That works out at around 40 cents / km charging from the grid in Cape Town)

Mostly PV in Summer.

2013 Nissan Leaf for sale. - SOLD Excellent condition. New tires. Odometer: 55 171 KM Range: 60 KM Charger: 3 Kwatt Location: Cape Town Efficiency: 7.5 KM / Kwh

SMA Sunny Mini Central for Sale with mounting bracket. Single Phase unit. R2000 EFT or cash. 6 month Warranty Happy to ship once funds clear. Located in Plumstead, Cape Town Carl - 084 677 1883

Looking for a 5 pin WiFi module for my Goodwe GW3648-EM Inverter Please let me know if you have one for sale.

Looking for a SMA Sunny Remote Control for my Sunny Island S8.0 Inverter. Please let me know if you have one for sale.

@BritishRacingGreenyou have inspired me to attempt a repair on a faulty Growatt SPF 5000 ES inverter. With MPPT board removed and only battery connected i noticed surface arcing around the Ceramic caps and the DC to DC Bus Side IGBT's located on the bottom of the middle heat sink. There is a fair amount of black dust on the board and some moisture on the fan unit and on the board. All the IGBT's and Mosfets test ok on the diode test function so hoping that damage is limited or best case no damage. Inverter came up with warning error 62. Please advise what is the best way to clean the board.

Question for the Technical Experts: What will happen if the solar array Negative is mistakenly solidly grounded. Will this fault cause the inverter to blow?

Following System Available: 1) 3 Kwatt Outback Inverter 2) Outback Flex Max 60 Amp Charge Regulator 3) Four 200 Amp Hour Batteries 4) AC Distribution Box 5) Battery Balancer 6) Stand The system has been temporarily assembled for demonstration purposes. Contact Carl - 084 677 1883

This is what the supply to my house (which is very old) and the geckos home looks like. Its a 2 core cable. The insulated centre conductor is the Live and the bare copper conductor surrounding it is the PEN (Protective Earth Neutral) Conductor. This is called a TNCS earthing system. The PEN conductor is connected to the Neutral Bar and this is earthed to the earth electrode and copper water pipes. The PEN conductor is also earthed at the transformer star point (supply point).

Price drop to R100 / set. Minimum Qty = 5 units. (Over 100 units available.) Equipment removed from a Body Corporate Complex as they upgraded to a Pre-paid metering system.

ABB C11 110-300 KWh meter and ABB ESB 40-20 AC / DC Contactor for sale. Asking Price for both units together - R200. Collection in Cape Town, Plumstead or happy to courier.

Sounds like you may have lost primary fluid in your vacuum tubes. (Could be the leak that @svendescribed at the header tank with ball valve) This would lead to a major decrease in overall efficiency of the system. UberSolar seem to have a unique indirect water heater system with a venting setup on the manifolds to limit the maximum stagnation temperature to below boiling point. (94 degrees C for Johannesburg). I have never seen or heard of this system before so have no idea of how well it will perform. In this particular system the vacuum tubes is filled with fluid which is separated from the high pressure council supplied water. Traditionally the fluid in the indirect system would consist of a mixture of water and glycol and would be used in areas with frost. An expansion tank would allow for volumetric changes as the water / glycol mixture heats up and primary fluid should never be lost or vented out of the system. It should be a closed system. In this particular case it sounds like some of the primary fluid might have been lost. On the Gerserwise controllers i have only had good experiences so far.

The maximum demand charge is actually based on the highest average demand (KVA or KW) during a 30 minute window period starting at midnight on the beginning of the month. So the billing period is broken down into 30 minute blocks and then you get charged for the block with the highest demand. Maximum Demand = kVA = kVAh/T (Where T = integration period of 30 minutes) So from this you can see that the starting current of motors will be an insignificant contributor to your maximum demand charge. So the trick is to reduce your energy consumption for any 30 minute block period.

Circuit Breakers can typically either have a thermal / magnetic or an electronic trip unit fitted. Some points to consider are: 1) Electronic trip units are far less affected by ambient temperature. 2) Thermal magnetic trip units typically have to be derated for ambient temperatures above 40 degrees C. (Eg. at 50 degrees, delta T = 10 degrees, 5% current derating) 3) Trip units are sometimes interchangeable for AC and DC circuit breakers. As @plonkster pointed out the thermal protection of the trip curves are identical since the bimetal strips are responding to the RMS value. The instantaneous protection against short circuits are influenced by the "ferromagnetic phenomena" which in tun is affected by the circuit breaker design and the way the poles are connected. ABB have a coefficient called "KM" that the instantatneous trip value for AC has to be multiplied with to obtain the DC values. This coefficient varies between 0.9 - 1.3 So coming back to @viceroyproblematic circuit breaker. 1) I would suspect that the breaker may have a high internal contact resistance which is causing localised heating near the bimetal strip. 2) Other factors such as undersized cabling (@Chris Louw), poor crimp connections, incorrectly tightened etc. will also cause localised heating resulting in a derating of the trip setting.

Technically this is called "Current Level Discrimination" and is a technique linked to the staging of the Long Time (LT) tripping curves of two serial-connected circuit-breakers. (Quoted from the Schneider Electrical installation guide) An interesting point is that overload protection of a cable can be implemented either at the source or at the load side but short circuit protection has to be implimented at the source. @plonksteris spot on.

Technically its a fault voltage that we come into contact with that will drive a current through us. Our impedance is determined by many factors such as the current path through the body, amplitude of the applied voltage, duration of the applied voltage, frequency of the applied voltage, contact surface area, pressure exerted and skin temperature. IEC 479-1 Table 1 (for the highest risk 5 % of the population) shows that the total impedance between dry hands varies from 1750 ohms at 50 V rms to 700 ohms at 1000 V rms. The impedance of an arm is very similar to a leg. So the values mentioned also apply for the current path from one hand to one foot. The more typical situation is where the current path is from one hand to both feet and then you can use 75 % of the bove impedance value. So start by measuring the fault / touch voltage.