MidNite Classic User manual

For help with the Classic or Classic SL, please see our how-to videos and extended documentation at
www.midnitesolar.com/documentIndex.php . Before calling tech support, we recommend visiting
this website for some of the most common issues.
WARNING: Arc Fault protection is not ON by default.
NOTE: The National Electrical Code article 690.11 requires Arc Fault protection. The Classic has
this built-in as standard equipment and will need to be enabled, if so desired. The Classic SL does
not have Arc Fault built-in.
NOTE: The Arc Fault protection has adjustable sensitivity and may require some tuning for your
particular system to avoid nuisance tripping. Some house loads like table saws and well pumps and
other motor loads can be seen on the PV circuit in the Classic appearing similar to DC arcs. We have
started with a general average we have found to work reliably but in some cases this sensitivity
level is too high causing false Arc Fault alarms. When the Classic goes into Arc Fault, it goes to
Resting and will not charge the batteries. Please consult the Classic Manual for enabling and fine-
tuning of the Arc Fault system.
DANGER OF DEATH TO YOUR CLASSIC!
When the Classic is used with wind or hydro, a Clipper-type device will most likely be needed to
protect against over-voltage. A battery-based diversion load WILL NOT keep the Classic safe from
over-voltage. High input voltage is recorded and over-voltage is not covered under warranty.
Never wire a pump or other load to the input side of the Classic. If a load must be wired to the input
side of the Classic, the load and Classic need to have blocking diodes on them.
Never parallel two Classics onto one PV array.
IMPORTANT –Per UL1741 and NEC 690.12, this device must be located where the PV input
conductors are not required to be controlled.
For larger systems with large inverters and or multiple inverters (i.e., Radian or XW+), it is
important to use appropriately sized cables and bus bars or damage to the inverters or charge
controllers can occur. Take a single XW+ E-Panel, for example, it has a positive bus bar for the
charge controller battery side connections. This bus bar is sufficient for two charge controllers; if
you need three or more, then you need to look at the best way to handle the amperage. A dual
Radian, for example, is actually four separate inverters. Properly sized cables as well as a large
enough battery bank is very important. Most manufacturers of battery-based inverters recommend
100Ah of battery per kW of solar modules. Please consult the inverter manufacturer for assistance
with cable sizing.
Classic SL
This Owner’s Manual covers both the Classic and the Classic SL models.
The Classic SL performs the same functions as the regular Classic, but WITHOUT the following
features: 1) No Arc Fault circuit; 2) No AUTO EQ function; 3) No Ethernet port; 4) No wind or hydro
programming; and 5) The Classic SL does not include the Battery Temp Sensor, sold separately.

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Classic 150 Classic 200 Classic 250

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Table of Contents
Introduction..................................................................................................................................................... 5
Safety Instructions............................................................................................................................................ 6
Standards and Requirements.................................................................................................................................... 6
DC and Battery-related Installation Requirements................................................................................................... 7
How to KILL Your Batteries........................................................................................................................................ 7
Classic Power Curves ........................................................................................................................................ 8
Classic Installation .......................................................................................................................................... 10
Unpacking the Classic.............................................................................................................................................. 10
Removing and Installing Classic Front Cover........................................................................................................... 10
Mounting the Classic............................................................................................................................................... 11
Alternative Mounting.............................................................................................................................................. 12
Sealed or Vented..................................................................................................................................................... 13
Wiring the Classic ........................................................................................................................................... 13
Maximum and Minimum Wire Size......................................................................................................................... 13
To Connect Wiring to the Classic ............................................................................................................................ 14
DC Terminal Connector ........................................................................................................................................... 16
Current Rating ......................................................................................................................................................... 16
Over-current Protection.......................................................................................................................................... 16
Long Distance Wire Runs......................................................................................................................................... 17
Connecting the Classic to the Clipper ..................................................................................................................... 17
Grounding...................................................................................................................................................... 18
Chassis Grounding................................................................................................................................................... 18
DC System Grounding ............................................................................................................................................. 18
DC GFP (Ground Fault Protection) .......................................................................................................................... 18
Disabling GFP........................................................................................................................................................... 19
Positive Ground Systems......................................................................................................................................... 19
Networking .................................................................................................................................................... 20
Follow-Me –Charge Coordination .......................................................................................................................... 19
Ground Fault Sharing .............................................................................................................................................. 21
Naming the Classic .................................................................................................................................................. 21
Addressing Classics.................................................................................................................................................. 21
Connecting the Classic to Two MNGPs/Network Cable.......................................................................................... 22
Connecting the Classic to the Internet.................................................................................................................... 22
Network Setup through the MNGP......................................................................................................................... 23
DHCP........................................................................................................................................................................ 24

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Static IP.................................................................................................................................................................... 24
IP Address................................................................................................................................................................ 25
Subnet / Gateway / DNS 1 ...................................................................................................................................... 25
Web Access ............................................................................................................................................................. 25
Local Network ......................................................................................................................................................... 26
Battery Temperature...................................................................................................................................... 26
Battery Temperature Compensation ...................................................................................................................... 26
Battery Temperature Sensor (BTS) Installation ...................................................................................................... 26
Classic Programming....................................................................................................................................... 27
Commissioning the Classic (Quick Start) ................................................................................................................. 27
MNGP Features and Programming ......................................................................................................................... 27
Battery Charge Stages ............................................................................................................................................. 29
Mode is Off.............................................................................................................................................................. 30
Adjusting Absorb, Equalization, and Float Voltages ............................................................................................... 30
Current Limit ........................................................................................................................................................... 30
LED Modes............................................................................................................................................................... 31
Calibrating Classic and PV Voltage .......................................................................................................................... 31
Configuring DC Input Source ................................................................................................................................... 32
Programming the Classic for Wind Input Source .................................................................................................... 33
Equalization............................................................................................................................................................. 35
Setting Date and Time............................................................................................................................................. 36
Arc Fault .................................................................................................................................................................. 36
Programming for PV Bleed Down ........................................................................................................................... 37
Charge/Advanced Settings...................................................................................................................................... 38
Auxiliary Ports................................................................................................................................................ 39
Configuring the Classic’s AUX Ports ........................................................................................................................ 39
AUX Function Definitions ........................................................................................................................................ 40
AUX 1 Modes........................................................................................................................................................... 41
AUX 2 Modes........................................................................................................................................................... 43
AUX 1 and 2 Jumpers .............................................................................................................................................. 45
Logged Data ................................................................................................................................................... 47
Graphical Logging Display Modes ........................................................................................................................... 49
Classic Voice................................................................................................................................................... 51
Levels of Chattiness................................................................................................................................................. 51
Programming Classic Voice ..................................................................................................................................... 51
Updating New Firmware to the Classic ............................................................................................................ 52

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Preparing Classic for Update................................................................................................................................... 52
HyperVoc ....................................................................................................................................................... 54
Troubleshooting / FAQs.................................................................................................................................. 55
Mechanical Specifications............................................................................................................................... 64
Electrical Specifications .................................................................................................................................. 65
Default Battery Charge Set Points ................................................................................................................... 65
Regulatory Approval ...................................................................................................................................... 66
RS232 Jack Pin Out ......................................................................................................................................... 66
Classic Breaker Sizing...................................................................................................................................... 67
Classic Menu Maps......................................................................................................................................... 68
Classic Label Set ............................................................................................................................................. 72
Glossary of Terms........................................................................................................................................... 73
Warranty ....................................................................................................................................................... 75
New Turbo Fan Assembly ............................................................................................................................... 76

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Introduction
The MidNite Classic charge controller is designed to regulate DC input from PV, hydro, or wind
turbines. For other DC sources, please contact MidNite Solar Tech Support. The Classic 150, 200,
and 250 are designed to work with 12V, 24V, 36V, 48V, 60V, and 72V battery banks. Voice
annunciations of operating values are now available in English (French and Spanish coming soon).
The Classic can be installed stand-alone or as a multi-unit networked installation. Standard features
of the Classic charge controller include:
Three input operating voltage ranges: 150, 200, and 250V
Multiple DC input options (solar, wind or hydro)
Voice annunciations in multiple languages
Data logging for 380 days
Graphical display
Internet-ready
Scope
This manual provides safety guidelines, installation instructions, and usage information for the
standard and SL models of the Classic 150, 200, and 250 charge controllers. It does not provide
brand specific information about photovoltaic panels, batteries, et cetera. Contact the manufacturer
of other components in the system for relevant technical data.
Este manual también está disponible en Español. La versión en Español puede encontrarse en
nuestra pagina web en la ficha Documentos y haga clic en Manuales.
Notice of Copyright
MidNite Solar's Classic Charge Controller User’s Manual
Copyright ⓒ 2019 All rights reserved.
MidNite Solar, Inc. reserves the right to revise this document and to periodically make changes to
the content hereof without obligation or organization of such revisions or changes unless required
to do so by prior arrangement.
Disclaimer
Unless specifically agreed to in writing, MidNite Solar Inc.: (a) Makes no warranty as to the accuracy,
sufficiency or suitability of any technical or other information provided in its manuals or other
documentation; (b) Assumes no responsibility or liability for loss or damage whether direct,
indirect, consequential or incidental, which might arise out of use of such information. The use of
any such information will be entirely at the user's risk.
Contact Information
Telephone: [phone]
Fax: [phone]
Email: [e-mail]
Web: www.midnitesolar.com

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Safety Instructions
WARNING: Identifies conditions or practices that could result in personal injury or loss
of life.
CAUTION: Identifies conditions or practices that could result in damage to the unit or
other equipment.
This product is intended to be installed as part of a permanently grounded electrical system as
shown in the system configuration sections. The following important restrictions apply unless
superseded by local or national codes:
To use the Classic’s built-in DC GFP, the system's DC negative conductor must not be bonded
to earth ground. The Classic does this with its internal Ground Fault Protection circuitry. The
battery negative and ground are not bonded together directly, rather battery negative and
ground are connected by the Classic’s internal GFP device. All negative conductor
connections must be kept separate from the grounding conductor connections. The
equipment ground terminal inside the Classic must be connected to earth ground for the
internal DC GFP to work.
With the exception of certain telecom applications, the Classic should never be positively
grounded.
The Classic equipment ground is marked with this symbol:
If damaged or malfunctioning, the Classic should only be disassembled and repaired by a
qualified service center. Please contact your renewable energy dealer/installer for
assistance. Incorrect re-assembly risks malfunction, electric shock, or fire.
The Classic is designed for indoor installation or installation inside a weatherproof enclosure.
It must not be exposed to rain and should be installed out of direct sunlight.
Turn off all circuit breakers, including those to the solar modules, batteries, and related
electrical connections before performing any maintenance.
Standards and Requirements
All installations must comply with national and local electrical codes; professional installation is
recommended. The NEC in the USA requires a DC ground fault interrupter for all residential PV
installations. The NEC requires an ARC FAULT detector on all charge controllers and inverters
operating above 80VDC. Both devices are built into the Classic.
The MidNite Solar Classic conforms to UL 1741, Safety for Inverters, Converters, Controllers and
Interconnection System Equipment for Use with Distributed Energy Resources, Second Edition, May 7,
1999 with revisions through January 28, 2010 and CAN/CSA C22.2 No. 107.1: 2001/09/01 Ed: 3
(R2006).

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DC and Battery-Related Installation Requirements
All DC cables must meet local and national codes (Reference NEC Article 480).
Shut off all DC breakers before connecting any wiring.
Torque all Classic wire lugs and ground terminals to the specs found on Page 14.
Copper wire ONLY with a rating of 75° C or higher.
Keep cables close together (e.g., using a tie-wrap) as much as possible to reduce inductance.
Ensure both cables pass through the same knockout and conduit to allow the inductive
currents to cancel.
DC over-current protection must be used on the Classic input and output circuits.
Breakers between the battery and the Classic must meet UL489 standards.
Breakers between the DC source and the Classic must meet UL1077 or UL489 standards.
Design the battery enclosure to prevent accumulation of hydrogen gas at the top of the
enclosure. Vent the battery compartment from the highest point to the outside. A sloped lid
can also be used to direct the flow of hydrogen to the vent opening. Sealed (AGM, Gel)
batteries do not normally require ventilation. Consult your battery manufacturer for details.
WARNING: Personal precautions during installation – Batteries present risk of electrical
shock, burn from high, short circuit current, fire, or explosion from vented
gases. Follow proper precautions.
Someone should be within range of your voice to come to your aid if needed.
Keep plenty of fresh water and soap nearby in case battery acid contacts skin, clothing, or
eyes.
Wear complete eye protection. Avoid touching eyes while working near batteries. Wash your
hands with soap and warm water when done.
If battery acid contacts skin or clothing, wash immediately with soap and water. If acid
enters an eye, immediately flood the eye with running cool water for at least 15 minutes and
seek medical attention.
Baking soda neutralizes lead acid battery electrolyte. Keep a supply on hand in the area of
the batteries.
NEVER smoke or allow a spark or flame in vicinity of a battery or generator.
Be cautious to reduce the risk of dropping a metal tool onto batteries. Doing so can short the
batteries or other electrical parts, resulting in fire or explosion.
Never wear metal rings, bracelets, necklaces, and watches when working with a battery or
other electrical circuits. A battery can produce a short circuit current high enough to weld a
ring or the like to metal, causing severe burns.
How to KILL Your Batteries
Batteries are delicate and require proper attention especially when off-grid. Think of your batteries
and solar equipment as a small nuclear power plant, hydro dam, or natural gas-fired power plant.
Just like any of those, your system needs DAILY attention to ensure it is performing correctly and
safely. For Lithium battery banks we highly recommend using the Logic input on the Classic which
allows the BMS to tell the Classic to stop charging if the BMS detects an issue brewing. We also
recommend the use of an independent battery monitor/alarm if you have an expensive battery
bank. Below is a list of some of the most common ways we have seen people kill their battery bank.

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Not watching the charge voltages or verifying you are charging to the voltage supplied by the
battery manufacturer.
Not verifying the temperature compensation neutral point (typically 25° C) and the milli volts
per degree C per cell (typically -5mV).
Not watching to verify the Absorb or EQ time is set properly and that the equipment actually
charges for that period of time. Some equipment will have settings like “End Amps” that can
terminate Absorb early and if set up wrong can damage a battery.
Not having enough charge current (Solar Panels) to properly charge the size of the battery
you have. Consult the battery manufacturer for the minimum charge current.
Using tap water or other liquids instead of distilled water in a flooded battery. The minerals
in the tap water will destroy a battery.
Failing to keep all connections clean.
Not using ALL EQUAL LENGTH interconnect cables on each string. It is important that ALL
strings be wired EXACTLY the same. Any variance in resistance on one string versus another
will cause an imbalance and the batteries will be dead in less than 6 months.
Using more than three parallel strings and not using common bus bars. When you use more
than three strings it is very hard to properly charge the middle strings. The only safe way to
do this is to wire each string with equal length cables to a common bus bar.
Not making sure your lead acid batteries get a full charge at least once a week.
Routinely using more than 50% of the capacity of the lead acid battery. Using more than half
the battery capacity drastically shortens the batteries life; occasionally is fine but on a daily
basis will kill them in months.
Not leaving ample space between cells for cooling. We recommend at least one inch between
the cells for cooling. Ask the battery manufacturer what they recommend.
Trusting a State of Charge (SOC) meter, which can lose calibration over time and give you
false readings. You need to verify specific gravity and or verify the charge voltage is being
met. Never fully rely on the SOC %; it is just a good, quick reference.
Classic Power Curves
Table 1

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Table 2
Table 3
Tables 1 through 3 above represent the max power output for a given input for each Classic. Using
and understanding these power graphs will help maximize the Classic’s output power and aid in
selecting wire and breaker/disconnects. Notice that lower battery voltages and lower PV input
voltages result in higher continuous output power. The PV voltages listed are for reference and are
not intended to be the only PV voltages supported. The battery voltages listed show common
battery bank configurations. Other voltages are also supported. The Classic battery voltage
parameters are fully user-adjustable.
Example: If you are using a Classic 250 and 48V battery bank, the maximum continuous output
power based on 25° C ambient is 55A when using a PV array that yields a maximum power voltage

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of 180V. The same set-up using higher voltage modules that result in a 200V maximum power
voltage will result in only 53A. Although 55A to 53A is not a significant change, it does indicate that
a lower input voltage is more productive. Design your system to achieve an ideal input voltage, or a
“sweet spot,” in terms of sufficient Voc for MPPT operations: not too low, not too high. Keep in mind
that an MPPT controller needs to have the open circuit voltage of the array about 33% higher than
the highest battery voltage you plan to charge to.
NOTE: You can find the Classic string sizing tool our web page www.midnitesolar.com.
Classic Installation
Unpacking the Classic
When you receive your Classic, you will want to unpack it and make sure everything is there and in
good shape. Refer to Figure 1. Included with the Classic:
Classic charge controller
Battery temperature sensor
User’s manual, printed
Knock out covers, 3 screened
Parts bag with stickers, terminal block cover, and silicone grease
Email [e-mail] for more information or if anything is missing or
damaged.
Figure 1
Removing and Installing Classic Front Cover
Removing the front art deco cover is required to gain access to the wiring compartment.
NOTE: A cable connects the cover to the electronics. Do not pull hard or fast as damage could occur.

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To remove the front cover of the Classic in preparation for installation, remove the four Phillip’s
head screws with a #2 Phillip’s screwdriver. Lift the front half of the Classic casting off. You will
need to unplug the display cable. It works the same as any phone cable.
When installing the cover for the final time, squeeze a small
amount of silicone grease (included in the parts bag) onto the
metal pins of the male jacks on the display cable before
plugging them in.
To re-install the front cover of the Classic you will need to
plug in the display cable and carefully route it around the
components on the circuit board as you set the cover in place.
See Figure 2. Do not force the cover if it does not seat into
place easily; stop and look for any cables or wires that may be
interfering. With the cover seated in place, install the four
Phillip’s screws with a #2 Phillip’s screwdriver.
Figure 2
Mounting the Classic
The following section covers typical mounting arrangements. If you require additional details that
are not covered here, please contact our tech support team. The Classic is designed to be directly
mounted onto the MidNite Solar E-Panel. The Classic can accommodate other installation methods
as well. Mount in an upright position out of direct sunlight when possible. For your convenience the
Classic has four one-inch knock outs that are pre-cast. The Classic has mounting locations and
conduit locations that are similar to other brands of charge controllers to facilitate ease of upgrading
older technologies.
Mounting the Classic to the E-Panel:
Remove the front cover of the Classic.
Install the mounting bracket on the E Panel and start the upper mounting screw into the
bracket, leaving it about half-way out so you can hang the Classic on this screw.
Install the one-inch close nipple into the E-Panel as shown in the E-Panel directions. The
one-inch close nipple, two plastic bushings, and three locknuts are included with each E-
Panel. One locknut acts as a spacer.
Carefully hang the Classic on the screw in the bracket and slide it over the close nipple
(see Figure 5).
Install the lock nut and bushing on the close nipple and tighten the screw in the mounting
bracket.
Do not install the front cover until you complete the wiring of the Classic.

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Figure 3 –Classic mounting bracket
Figure 4 –Classic mounted to E-Panel Figure 5 –Nipple, locknuts, and bushings
Figure 6 Install locknut here to act as a spacer.
Alternative Mounting
To mount the Classic to a plywood surface, use 1 1/2” wood screws in the top keyhole slot hole and
the holes in the wiring compartment, taking care to make sure the Classic is plumb and level.
IMPORTANT!
Do not mount in a zero clearance compartment.
Overheating may result. The Classic produces heat
in normal operation. Airflow around the Classic is
required to prevent overheating and shutdown.
This is especially true in hot environments.

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Sealed or Vented
The Classic can be sealed for protection from salt air or dust. It comes from the factory vented. If
you live in a dusty or salt air environment, you may wish to seal the Classic. Sealing the Classic does
not make the unit water resistant. To seal the Classic, install the solid plastic knock-out covers into
any unused knock-outs and snap the upper vent cover onto the Classic as seen in Figures 7 and 8.
Note that the Classic will be slightly de-rated (will put out less power) by sealing it. Refer to the
specifications page of this manual for the ratings in the sealed mode (40C+, shown in Table 6). To
obtain the parts necessary to seal the Classic, please contact our Tech Support Team and ask for
MNCLSEALKIT.
Wiring the Classic
WARNING - SHOCK HAZARD:Disconnect the batteries and input power before opening the Classic
front cover. ALWAYS use proper over-current protection and disconnects on the PV+
and battery + wires.
Ensure all source and battery circuits are de-energized and wait five minutes before working on the
wiring in the Classic. The Classic has two common neutral (negative) terminals; therefore, only one
neutral conductor is required to run from the E-Panel and terminate on either (or both) common
neutral terminal. This negative conductor should be sized to match the battery + cable. The positive
DC source wire goes to the PV+ setscrew. The positive battery DC wire goes to the battery +
terminal. Torque the terminal screws to the specs below.
Connect ONE PV array per Classic.
NOTE: The Classic should be wired by a qualified professional and needs to meet all applicable
electrical codes.
Maximum and Minimum Wire Size
The Classic’s blue DC terminal connector will accept wire from #14 to #4 AWG (use THHN;
#4 AWG welding cable will not easily fit into the terminal block).
The Classic’s AUX 1 and AUX 2 terminal connectors will accept wire up to #18 AWG.
Figure 8
Figure 7

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To Connect Wiring to the Classic:
Ensure the DC source and battery are disconnected.
Connect a grounding conductor between the Classic and system ground.
Ensure the breaker between the battery and Classic meets UL489 standards.
Ensure the breaker between the DC source and Classic meets UL1077 standards.
Use copper building wire ONLY.
Connect the DC source and battery wires to the Classic.
Connect any communications cables or auxiliary input/output wires.
Torque terminal connector setscrews to the following specs:
oUp to #10 AWG: torque at 25- to 35-inch pounds.
o#8 AWG: torque at 30- to 40-inch pounds.
o#6 AWG or larger: torque at 40- to 50-inch pounds.
Diagram 1 Explanations:
10 - Solar modules (PV).
11 - DC combiner (i.e., MidNite MNPV6 or MNPV12).
12 - MNSPD300-DC (Surge protection).
13 - MNSPD300-AC (Surge protection).
14 - MNSPD300-DC (Surge protection).
15 - DC breaker for the inverter (Also serves as a disconnect for the Inverter).
16 - DC breaker for the PV into the Classic (Also serves as a disconnect for the Classic).
17 - DC breaker for the battery into the Classic (Also serves as a disconnect for the Classic).
18 - AC L1 input bus bar (This is where the generator L1 input gets wired).
19 - AC neutral bus bar (This is where ALL AC Neutrals get wired).
20 - AC L1 output bus bar (i.e., L1 output to the load center for the building).
21 - Battery positive bus bar (This is where you wire the battery positive side of the Classic,
as well as where you wire up DC loads. Do NOT wire the battery cable to this bus bar).
22 - Earth ground busbar (This is the common earth ground bus bar where all the grounds
get wired back to and it needs to be connected to the building’s ground rod system).
23 - PV positive bus bar (This is where the solar panels positive lead connects).
24 - Battery negative bus bar (This is where the solar panel negative lead goes as well as the
Classic’s negative lead and any negatives from the loads. Do NOT connect the battery
negative cable to this bus bar.
25 - DC shunt (The shunt measures the amperage in or out of the battery. You connect the
battery to one side and everything else to the other side).
26 - Earth ground system of the building.
27 - Classic charge controller.
28 - AC generator.
29 - Batteries (The voltage must match the voltage of the inverter).
30 - Classic temperature sensor.
31 - DC cables to inverter.

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Diagram 1 –Overall System Wiring

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DC Terminal Connector
The Classic's DC terminal connector is located on the circuit
board as shown in Figure 9. The connector is rated for
copper conductors and will take up to a #4 AWG wire
(THHN). #4 AWG THHN when installed in the Classic and
MidNite E-Panel is rated for over 100A and is therefore
suitable for the highest power available from the Classic
150. After installing the wires for the last time, snap in the
blue cover that is included in the parts bag.
Current Rating
The Classic limits the output current based on the model:
Classic 150 – 96A maximum
Classic 200 – 79A maximum
Classic 250 – 61A maximum
Over-current Protection
The Classic must have over-current protection to protect wiring from over-current events. A means
of disconnect must be installed on the DC in and DC out of the Classic. Consult your local codes to
determine over-current ratings. The breaker between the battery bank and the Classic must
conform to UL489. The breaker between the DC source and the Classic must conform to UL1077or
UL489. The NEC requires 1.56 times short circuit current (Isc) for PV over-current protection. This
is reduced to 1.25 times when using a breaker rated for continuous duty. All MidNite Solar breakers
are rated for continuous duty (100% rating). No de-rating is required for the input or output
breakers when using MidNite Solar DC breakers.
Solar panels can produce more current than their name plate rating in extreme situations, so the
safe minimum wire size should be selected for the PV array maximum short circuit current. Please
consult your PV manufacturer for specifications. The US National Electrical Code requires 1.56
times the PV short circuit current for wire size on the PV input. Output wire size follows the NEC
guidelines. Typical wire size for output is #6 AWG for the Classic 250 and #4 AWG for the Classic
200 and 150; check all de-ratings for your wire type and installation method.
The over current devices, wiring, and installation methods used must conform to all electrical codes
applicable to the location of installation. Wiring needs to be protected with proper strain relief
clamps and or conduit. See Page 66 for a breaker and wire size chart.
The network cables, USB cable, BTS cable, and auxiliary input/output cables should run in a
different conduit to preserve their signal. When installing the Classic in a MidNite E-Panel, it is
acceptable to run all wiring through the same knockout hole. It is legal to run signal and power
wires together if all wiring is listed for the highest voltage to be encountered.
NOTE: Follow all local codes.
Figure 9 –Terminal Block

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Long Distance Wire Runs
The Classic offers some unique opportunities if you are faced with longer than normal wire runs
between the DC source and the Classic. The Classic comes in three input voltage ranges letting you
design a DC source at a higher voltage if it is beneficial. For example, let’s say you have a 300-foot
run from a PV array to the Classic. You could wire for an open circuit voltage close to 250V
accounting for the coldest temperature you will encounter. This will allow you to run a smaller
gauge wire than with a lower voltage charge controller. The efficiency of a high voltage Classic is
less than the lower voltage versions, so you need to weigh the benefit. If this sounds too
complicated, use this rule of thumb in selecting the proper Classic: PV runs up to 100 feet - use the
Classic 150; runs up to 180 feet - use the Classic 200, or above 180 feet - use the Classic 250.
If the wire size between the DC source and the Classic is larger than the Classic's DC terminal
connector, you can use a splicer block or similar connector to reduce down to #4 AWG close to the
Classic. The MidNite E-Panels are supplied with a PV input bus bar that accepts up to # 2/0 AWG
wire.
Connecting the Classic to the Clipper
The connections between the Clipper and Classic are simple. There are the DC – and + conductors
from the Clipper to the PV input on the Classic. There is also a smaller set of – and + conductors
connecting AUX 2 to the PWM input on the Clipper.
Diagram 2 –Classic and Clipper Wiring

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Grounding
Chassis Grounding
In all installations the Classic chassis should be connected to ground. For systems with a battery
breaker sized 60A and smaller, #10 AWG (6 mm2) copper is generally sufficient. For systems with a
battery breaker sized 100A and smaller, #8 AWG (10 mm2) copper is required. For grounding
conductor requirements on your specific installation, please consult your local electrical code. The
chassis grounding terminal is in the upper right corner of the electrical connection compartment.
DC System Grounding
The Classic is designed to work with negative ground, positive
ground, or ungrounded power systems. In negative ground
systems, DC negative may be connected to ground either
externally or by using the Classic’s internal grounding jumper,
shown in Figure 10. The internal grounding jumper should
only be installed when the Classic’s GFP is enabled. When the
chassis ground point is connected to earth ground and the GFP
jumper is installed, a DC negative to ground bond exists.
In a positive ground system or for an intentionally ungrounded
system, the GFP jumper must be removed.
Also note that with positive ground there will be items
still referenced to battery negative that can complete a
short circuit of the battery bank. These items include, but
are not limited to, the USB Cable and RS232 serial data lines.
DC GFP (Ground Fault Protection)
The Classic has internal ground fault protection (GFP) built-in. Since 2008, the NEC requires a DC-
GFP on all PV systems in the USA. The built-in DC-GFP eliminates the need to purchase and install
an external DC-GFP. If the internal grounding jumper is installed in a Classic, the battery negative
and DC source negative must not be connected to the system grounding conductor anywhere in the
system. Grounding of these circuits will defeat the GFP function. In a network with multiple Classics
connected in Follow-Me, only one Classic should have its internal grounding jumper installed and all
should have GFP enabled. The factory setting will make a DC negative-to-system ground connection
in the Classic. Disabled the GFP function for positive ground or an ungrounded DC system.
The ground fault device is simple to understand and use. It
detects a fault between battery/PV negative and earth ground
just like the breaker DC-GFP system. The difference with the
Classic is that it turns off the charge ability and sounds a loud
warning when a ground fault is detected. The Classic’s system
consists of a PTC that is between the negative and ground
internally in the Classic. A PTC is a self-healing fuse that will
open when current exceeds its rating and reclose when
current is dropped below its rating. The Classic will monitor
Figure 10 –Chassis Ground Point
Figure 91 –GFP Jumper

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this PTC and disable the charging when it opens. When the fault is cleared the Classic will restore
charging. To disable the internal ground fault protection function, the jumper labeled GFP needs to
be removed and the GFP function needs to be disabled in the TWEAKS menu. See “Disabling GFP”
for instructions.
Disabling GFP
The GFP feature should only be disabled to operate the Classic in an ungrounded power system or in
systems where GFP is not required.
Depress MAIN MENU key.
Scroll to the right or left until TWEAKS is highlighted and depress ENTER.
In TWEAKS, depress the RIGHT SOFT key to get to the MORE menu.
In MORE, scroll until GFP is highlighted.
Use the UP and DOWN ARROW keys to toggle between on and off.
Depress ENTER to save.
To reset the internal GFP function after detection has occurred: fix the actual ground fault, then turn
off the Classic and turn it back on (via circuit breaker between Classic and battery bank).
Positive Ground Systems
When installing the Classic in a positive ground system there are a few extra steps that need to be
taken. The ground fault jumper needs to be removed, and ground fault needs to be disabled in the
TWEAKS menu.
The overcurrent protection needs to be done a little differently as well. The input and output
breakers need to be double pole breakers. Battery negative and positive conductor both need to be
protected. Refer to Classic Breaker Sizing on Page 67.
CAUTION: Do not connect both positive battery and positive PV input to ground. One or the other
positive (normally battery +) but not both, otherwise, the Classic input and output will be
shorted.
Networking
Follow-Me Charge Coordination
Follow-Me allows Classics to share charge stages, battery temperature info, and ground fault
coordination. Follow-Me also allows you to program a single Classic for Equalize charging and it
will instruct all the others to Equalize as well. You do need to set the Equalize parameters in each
Classic. You will only need one BTS and it can be on any of the Classics.
WARNING: MidNite HIGHLY recommends using Follow-Me with two or more Classics. Best for
battery bank health. All firmware should match across all Classics.
WARNING: Reversed Follow-Me cables can damage the Classic if left in place for extended periods
of time and will not be considered under warranty. Please verify the proper operation
of Follow-Me during the initial set-up.