3 Main Compartment

3.1 Introduction

The Main Compartment contains all central parts and functions of eSite x10 such as rectifiers, solar converters, control unit, sensors and IOs, and modem. It is sealed and tamper-proof, which prevents users from opening the unit and unintentionally damage it. It also protects the users from dangerous voltage.

eSite x10 can use grid and genset to provide power to the customer load. Solar panels can also be used with eSite x10.

The Main Compartment is available in different variants. It can be equipped with rectifiers with soft-switching ATS functionality and solar converters, or it can be without solar converters. Expansion variants can be used to increase rectifier capacity.

Warning

Do not open the Main Compartment. Opening the Main Compartment can result in serious injury. The Main Compartment does not contain any user serviceable parts.

Caution

The Main Compartment is designed to be connected to the Connection Compartment only, unless a written statement from eSite Power Systems lists additional connectivity devices. The use of third-party connection devices requires explicit consent and approval by eSite Power Systems. The entire Connection Compartment and the power connectivity is subject to regulatory control by eSite Power Systems.

Caution

In case of failure or performance deviations, the Main Compartment must be returned to eSite Power Systems along with a replacement report. A Return Material Authorization (RMA) number is provided from eSite Power Systems. The RMA number must be clearly labelled on the returning box to eSite Power Systems for the warranty issue to be processed.

3.2 Rectifiers

3.2.1 Silicon Controlled Rectifier (SCR) with ATS functionality

The Main Compartment converts the AC supply via three rectifiers into -48V DC. The rectifiers provide 3.5 kW per unit, total 10.5 kW. The inputs from the AC sources are continuously measured to ensure that the most efficient AC source is used. The switch between the connected gensets/grid is automatic.

The eSite x10 patented Silicon Controlled Rectifier (SCR) is designed to improve the performance of the system compared to a traditional Automatic Transfer Switch (ATS). Both an ATS and SCR allows switching between two AC sources, but while the ATS is based on mechanical switching, the SCR uses power semiconductors.

Advantages of SCR

• No moving parts that are sensitive to dust and wear.

• Unlimited number of cycles.

• Automatic control of the AC input with adaptable thresholds remotely through eSite Tools.

• Overvoltage protection. Input with overvoltage condition is immediately disconnected to protect the rectifier and eSite x10 from wiring faults.

• No separate voltage supply is required for SCR to operate.

• No manual by-pass switch is required. SCR is incorporated into the eSite x10 and the power lines run separately.

• Individual control of each AC phase. One SCR per rectifier.

3.2.2 Electrical protection

eSite x10 is equipped with extensive high voltage protection. It withstands electrical hazards such as lightning induced voltage spikes, malfunctioning gensets, or poor grid stability. It is not only prevented from causing damage, but all incoming surge energy is converted into useful energy. The protection is automatic with no need for a manual reset.

Figure 3.1 illustrates electrical surges from the grid and/or genset(s) divided into different areas.

Figure 3.1.

1. Surge pulses usually caused by lightning. Gas discharge tubes are used in the input AC stages together with varistors and capacitors to dampen the pulse to a manageable level.

2. Combination of surge pulses from lightning and voltage spikes from the grid due to inductive switching, poor grid stability, and long transmission lines. The spikes can also derive from gensets with malfunctioning Automatic Voltage Control (AVR). Carefully selected components in the SCR absorbs these pulses without breaking the affected components.

3. Long lasting voltage increases from the grid and gensets. Increases can be caused by incorrect wiring resulting in 400 V AC instead of 240 V AC. SCR disconnects the voltage source. The voltage is constantly monitored and when in the allowed range, the voltage source is automatically reconnected.

Figure 3.2 shows surge areas in which the rectifier system in eSite x10 are protected. The rectifier system on eSite x10 is protected from disturbances located in all three areas (A, B, and C).

Figure 3.2.

The only regulatory demand for rectifiers is to be protected from electrical surges in area A. With additional Surge Protection Device (SPD) area B can also be protected but region C remains unprotected.

3.2.3 Rectifier efficiency and derating

The current limit is 19 A for each rectifier, due to that the power output will be reduced at lower AC voltages. The graph below shows the power derating vs input voltage below 45 °C.

Figure 3.3. Power derating vs input voltage (@T < 45 °C).

The peak rectifier efficiency is at 95 %. The overall power system peak performance is at 94 %. The graph below shows the rectifier efficiency measured in watt per rectifier.

Figure 3.4. Rectifier efficiency vs converted power.

3.3 Solar converters

A Main Compartment with solar converters is available.

Power from the solar panels is converted via three solar converters into -48V DC, each converter provides 2 kW, total 6 kW. The solar converters consist of a non-isolated step down DC/DC converter and is protected against ground faults, reversed polarity, and over voltages.

Each converter has high performance Maximum Power Point Tracker (MPPT) algorithm that continuously maximizes power output from the panels. The solar converters are tightly integrated with the rectifiers and the battery charge strategies to always optimize the use of solar power.

3.4 Convection cooling

eSite x10 is cooled using passive convection cooling. The solution is constructed to perform adequate cooling without fans, filters, or moving parts.

Convection cooling benefits
All electronics are sufficiently cooled.
No power is needed for cooling.
Minimized maintenance and no moving parts that require repair.
Totally silent.

Figure 3.5. The eSite x10 convection cooling functionality.

3.5 External interfaces

All external hardware interfaces on the eSite x10 are located on the Lower Main, which is part of the Main Compartment but accessed through the Connection Compartment.

Access to site for configuration, site information, and troubleshooting can be done remotely or locally. Locally, the site can be accessed via Wi-Fi or LAN using smartphone or laptop. Remotely, this can be done using the built in modem and eSite Tools. This requires an installed SIM card for mobile network communication. SIM card is not included in the product.

An overview of the Lower Main is shown in figure 3.6, with important parts marked and identified as follows.

Figure 3.6. The Lower Main

A I/O screw terminals B LED 1–3 C Ethernet socket D Antenna socket 1 – GSM antenna E Antenna socket 2 – Wi-Fi antenna F 1 USB port used for software updates (not used for mobile phone charging) G SIM card holder

3.6 Technical specifications

AC Input
Nominal AC input	230–250 V AC
Permitted AC input range	85–300 V AC
Frequency	45–65 Hz
Input current	3 x 19 A
Power factor	>0.99
THD	<5 % at 230 V AC, 100 % load
Input voltage derating	Linear derating for each phase, 3500 W @ 190 V AC, 1500W @ 85V
Protection	Varistor transient protection of all phases towards neutral. Varistor and GDT transient protection towards protective earth. Solid state transfer switch for long duration over voltages.

DC Output
Operational range	-42 – -58 V DC
Rectifier capacity	3 x 3500 W
Output power	10500 W
Current	195 A @ 54 V
Max current	235 A
Output Power Derating by Ambient Temperature, Continuous Operation (230 V AC)	Continuous power at 45 ⁰C: 9750 W Continuous power at 50 ⁰C: 8500 W
Output Power Derating by Ambient Temperature, Cyclic Operation (230 VAC). Full power is available again after a cooling period of ~45 min.	Full power at 45 ⁰C for 65 min, then derating to 9750 W Full power at 50 ⁰C for 40 min, then derating to 8500 W
Rectifier peak efficiency	95 %*
DC power system efficiency	94 %
DC power port for Low Priority Load	7000 W
DC power port for High Priority Load	3000 W

*The value includes an integrated static transfer switch.

Solar Converter
Nominal input voltage	125 V DC
Permitted input voltage range	50–150 V DC
Maximum input current	3 x 20 A
Power conversion capacity	6,6 kW
Power conversion peak efficiency	> 96.5 %

Environmental
Nominal Temperature	- 20 – + 45 °C
Operating Temperature	- 20 – + 50 °C
Storage Temperature	- 40 – + 70 °C
Relative Humidity	0–99 %
Cooling	Passive Convection Cooling
IP Code	Main Compartment IP65 Connection Compartment: IPx4
EMC	ETSI EN 300 386 V1.6.1
Safety	IEC/EN 60950-1:2005+A1+A11+A12+A IEC/EN 60950-22:2006-A
Environmental standards	ETSI 300 019-1-2 Class 2.3 Public Transportation ETSI 300 019-1-4 Class 4.2H Stationary use at non-weather protected locations – extremely warm and dry CE and RoHS compliant.
MTBF	>350 000 h (@T ambient 25 °C) according to Siemens SN29500

Communication ports
I/O	4 Digital outputs; 8 Digital inputs; 4 Analog inputs
External Bus	CAN; RS485; Ethernet
WLAN	Wi-Fi access point as service interface; SMA Connector
Radio modem	UMTS/HSPA: 850/900/1900/2100 MHz GSM/GPRS/EDGE: 50/900/1800/1900 MHz
Service port	Ethernet
Isolation	3.0 kV AC mains – Earth 1.5 kV AC mains – Sec 707 V DC mains – Earth

The sensor configuration on site depends on the selected options and settings. All the I/O screw terminals are protected against reversed polarity and short circuits.