Back feed circuit breaker solar. Aug 26, 2022 · A circuit breaker is an easy fix.

Back feed circuit breaker solar The breaker should be located on the end from where the power is coming from. Seems to me that the breaker should meet the requirement to protect the circuit from overcurrent. ) 20 amp breaker has 15 micro inverters 13. PU01200001E Effective May 2010 Reverse-feed applications for circuit breakers eaton Corporation www. Plug-in type back-fed circuit breakers connected to a stand-alone or multimode inverter output in stand-alone systems shall be secured in accordance with 408. Oct 22, 2014 · Plug-in type backfed circuit breakers connected to a stand-alone PV system are not required to be secured in place by an additional fastener that requires other than a pull to release the breaker from the panelboard. Breakers/fuses are required on all wires. May 31, 2014 · Here’s another reason for having a qualified electrician complete the work. Connect one end of the power cord to the 120/240-volt outlet on the generator. Nov 7, 2024 · Is the "Barn" breaker in the Main panel interlocked with the Main/Grid breaker such that only one of the breakers can be closed. eaton. There are some situations where the circuit breaker would need replacing, but those are rare and generally involve replacing the circuit breaker with a higher . A loose fitting breaker can cause the bar to burn a bit and ruin the connecting surface. Then at the panel the 100a breaker would protect the panel as that’s the maximum load you can run through the panel. They back feed solar and battery power into the panel. Re: Back feed circuit breaker In the 2011 code: 690. A whole house standby generator (Generac) will run your house as long as you have fuel (connect it to propane or natural gas). It is a certified breaker with Australian SAA ratings and IEC 60947. The 120% Rule back-feed limit for solar is calculated as: MAX SOLAR BACKFEED CALCULATION: (BUSBAR RATING x . The Inverter output is AC since the DC circuit has already been converted to AC electricity. Once a circuit breaker trips, you turn it back on by flicking the switch. 6 out of 5 stars 38 100+ viewed in past month Aug 14, 2020 · The breakers serve mainly as isolators and for lightening protection with the circuit consisting of PV Panels -> breaker -> Surge Protection Device (MOV) -> Inverter. The wiring in your home could then become overloaded, overheat, and start a fire. Apr 15, 2024 · Load side solar interconnections involve wiring your solar power system to an existing electrical panel. Jul 11, 2013 · ('111 Code) \:690. In this case a 6 or 8 circuit solar combiner/sub panel to combine all the arrays will allow him to connect all of them to 1 2 pole 40A breaker and feed the 200A panel no problem. Application Note: Determining the Circuit Breaker Size Circuit Breaker Specifications These tables describe criteria for circuit breakers in three phase inverters and three phase inverters with Synergy Technology. Dec 12, 2024 · Ability of circuit breakers to be reverse fed Product Line: Circuit Breakers Resolution: Any circuit breaker that does NOT have Line and Load (or + and - on DC breakers) identifying markings may be reverse fed. Is there a 'universal" type of No problem. As you flick the switch, the circuit is restored, and power continues to flow. And if utility ever upgrades it will be ready to accept other breakers. g. I had an electrician come out to diagnose the problem, and they advised me to turn off the solar system to prevent further damage to the panel. May 26, 2021 · Hello all . 11. You can also lower your main breaker, for example switch the 200 to 150, then that gives you an extra 50 amps of solar capacity. Nov 27, 2017 · Basically, a main breaker has to be bolted to a panel. Wow, that's a lot more information than I was expecting! To be clear, I'm not putting in a subpanel, I was simply thinking about using a 120v generator to feed into both legs of my main panel and then thought that the presence of a subpanel would mean that the neutral between the main box and the subpanel would mean that both separate 120v legs would be returning over that common neutral back Apr 5, 2012 · Note, solar and powerwalls are installed at the bottom. Mar 6, 2024 · The 120% rule focuses on the relationship between the solar back-fed breaker and the main breaker, ensuring that the electrical system remains within safe operating limits. Green fork has all good points save one: when back feeding your panel you ALWAYS put the back feed breaker on the opposite side(99 times out of 100, this is the Bottom) of the service / panel. Adding solar back feeding your panel through a circuit breaker in the panel adds additional current into the main panel coming fro the inverters. If you do that, you will need to use a hold-down kit to hold the breaker in. " My questions are: Jan 30, 2024 · This video goes over one of six options to connect solar panels or batteries on the load side of the service disconnecting means. 25 I Nov 7, 2024 · Is the "Barn" breaker in the Main panel interlocked with the Main/Grid breaker such that only one of the breakers can be closed. If you inject the solar power in just after the main breaker, the 200amp utility power can add to the solar power and potentially melt the buss in the load center if more than 200amps of load happens. 3. Feed a 200A panelboard with 200A from both sides, and you have 400A flowing among all the branch breakers, even if it never exceeds 200A on any cross section of busbar. That's backfed PV + load breakers. To shut off the inverter, page 86 of its manual shows to - First turn off the DC switch, - Second turn off the back-feed circuit breaker at the house panel If later, I want to turn the system on again; page 85 shows to - First turn on the back feed circuit breaker at the house Feb 2, 2022 · It feeds a Reliance transfer switch next to the main breaker, which has 6 switches to feed 6 circuits in the house, just throw the switch and the circuit is disconnected from the mains and is fed from the solar, easy as can be. I’m just trying to figure out how this works. Publication. That OCP matches service size. 5 amps This would come to 70 amps adding all the breaker but the actual amps it will be handling are 45 amps. ) 15 amp breaker has 10 micro inverters 9 amps 2. Nov 6, 2019 · I've learned that AC disconnects can be fused or unfused. It is essentially providing power “backwards” into the distribution bus. So, 40A back-fed breaker / 1. ) 15 amp breaker has 10 micro inverters 9 amps 3. Aug 14, 2023 · Backfeed refers to the redirection of electrical current, allowing it to flow in the opposite direction—moving from the solar power source toward the household circuit breaker. It does not matter to the AC breakers function however to be backfed. But , many solar systems I see simply backfeed on a double pole breaker into the panel and the main always stays on. Plus the 25% code requirement means 78. 80 = 75 amps ~ 80 amp branch circuit rating Also, with MPPT controllers, the battery bank voltage also changes the amount of current from the MPPT controller Nov 30, 2019 · How does a split bus bar electrical panel (often referred to as a farm panel) effect the solar backfeed circuit breaker size with the NEC “120% rule” or NEC705. In such a situation, the 120% rule solar ensures that the combined amperage from the grid electricity and solar panels does not overload the existing main service panel. Released for: Schneider Electric USA However, it is important to note that residential breakers with arc fault (AF) and ground fault (GF) capabilities are NOT suitable for back feeding. So yes. 12(B)(2)(3)(b)? An 18. 25 = 32 AMPS. A back-fed circuit breakers in the panelboard shall be positioned at the opposite end from the main circuit breaker and marked with a warning label at the back-fed breaker from the PV system. Sep 9, 2015 · I am also unsure why the tie breaker (back feed into the service panel is not positioned in the furthest breaker position on the original service panel. Rolland next steps for a panel back feed is to de-rate the main breaker to something less than 200 amps. May 29, 2009 · Back feed calculations All UL listed PV grid connected inverters will have installation instruction and perhaps a label that specifies the maximum fuse/CB to be used for the AC connection. See the compiled list below: Breakers that can be back fed and exceptions (This is a work in process list, it is probably not inclusive and does not yet include legacy breakers): HOM (Excludes those with suffix GFI, EPD, AFI, CAFI and DF. Apr 20, 2013 · The issue is his 1 kw system puts a little over 4A but has a 15A circuit breaker. The circuit breaker is technically called an Over Current Protection Device, or OCPD. Most panels will allow you to backfeed a branch circuit breaker and use that as a main breaker for the panel. When the inverter starts up, part of the self test routine will verify that the protection is functional, but if there is an external gfci on that circuit that doesn't know a test is happening, it will trip. The sum of all breakers rule, a separate guideline, states that the total amperage of all breakers in a panel shouldn't exceed the main breaker's rating; however, solar There IS a sensible, safe, legal middle ground between backfeeding and a full-blown (and expensive) transfer switch: a circuit-breaker panel interlock switch. Since the solar will be on the utility side of the main breaker, and since you say you are using a generator interlock so the main must be off while on generator, the solar will be connected to the utility side and will not talk to the generator. Feb 3, 2024 · I think with 200A busbar and 200A main breaker, this alternate rule lets you stuff the breaker panel with 200A total of branch circuit breakers. Feb 5, 2022 · By the rules, the back feed breaker must by at the far end of the bus bar away from the main grid breaker. Finally, divide the breaker size by 1. For example, if the bus rating is 225, then 120% is 270, and you could back-feed up to 70 amps while keeping the 200 amp main breaker. Sep 15, 2012 · Some manufacturers furnish 225 amp or higher rated bus bars in a panel supplied with a 200 amp main breaker. Nov 1, 2023 · I'm going to be adding a small sub-panel. Jul 19, 2024 · 2 IQ 5 Batteries connected in parallel 10kW are they wired as a 40A circuit or individually at 20A each having own circuit breaker? Battery woolf_4244 June 3, 2024 at 7:12 PM Number of Views 54 Like I couldn’t put a 150a breaker on my sub. I will have a breaker in my panel for the AC circuit feed, so I'm wondering if there is any reason to have a fused AC disconnect. Jun 15, 2011 · The breaker on the line side of the panel feeder and the solar inverter breaker both feed the panel. I'm assuming something like a farm panel with feed-through lugs and 8-spaces. A backfeed breaker can be used to connect a solar PV system to the load-side of a service. View attachment 531799 A back feed circuit breaker is the circuit breaker(s) solar and/or Powerwalls are connected to in the panel. Aug 11, 2006 · The normal load-side lugs of the back-fed main circuit breaker actually become the (incoming) line lugs of the panelboard, and power flows to the panelboard bussing through the branch connectors of the panelboard interior, to which the back-fed main breaker is connected. Inverter . The purpose of an over current device is to protect the conductors, be it a branch circuit or a bus bar, let's use hypothetical values, the total current capacity of all the branch circuit breakers in the in the panel probably exceeds the value of the main breaker, rationale is, it would be highly unlikely to have all circuits are drawing maximum load at any one time. So, if you have a 60 amp capable charge controller (and solar array), then the suggested branch circuit wiring+breaker rating would be: 60 amps * 1/0. That is in addition the the 200 potential amps coming in from the utility which a 200 amp main disconnect allows to your panel. That makes it a big problem if that last space in the panel is damaged. 36(D). If you did not have the solar feed the main grid breaker would pop, but with the backfeed from solar the maximum bus current could be grid breaker plus the solar feed breaker max. If the solar breaker and the generator inlet breaker were adjacent it would not be too difficult. Circuit breakers marked “line” and “load” shall not be back-fed. Circuit breakers that are marked line and load shall not be backfed Jan 12, 2020 · This is not right. The correct answer is: b) False. 100A through a 20A breaker. ) 20 amp breaker has 15 panels 13. AC is alternating current therefore you can not limit it to one way. ) 15 amp breaker has 10 panels 9 amps 2. In the given example, we are limited to 32 Amps which equals 7. Many cheaper breaker panels have tin plated aluminum bus bars. But I could feed it from a 150a breaker as long as the lines running to my sub panel can support 150a. The sub-panel itself will only hold three breakers. Normal Breakers have a load side and a line side with the load side attaching to a panels bus bars. 12(B)(3)(2 Jul 12, 2020 · Problem is that for the 20% backfeed rule to apply the backfeed point has to be at the end of the chain (bottom of the load center buss). Simple. 26 amps out of the panel will require a perfectly clear day on the equator at high noon. But the generator inlet needs to be adjacent to the main for interlock and the solar will typically be at the other end of the bus. the rest of the breaker where tandem Depending on the amperage of his back feed circuit he doesn't necessarily need wires rated as high as the main panels bus bars such as a 200amp house panel. For instance, you take the main breaker down to 175 amps, you can now back feed the 200 amp panel up to your 240 amp max bus bar. Jan 17, 2024 · Turn off the primary circuit breaker to reduce the building’s power supply. If you plug your generator directly into a wall outlet, then the wiring in your home is no longer protected by a circuit breaker or fuse in your power panel. This issue only came to my attention because my tesla car charger breaker was tripping very often. A lower ampacity device can be used if it meets the 125% rule for inverter output current based on PV array rated watts, inverter efficiency, and the low Mar 12, 2014 · Back-Fed Circuit Breakers. In solar many times the current will flow in both directions and thus need a breaker at both ends. - the unfused variety basically being a large power switch. 5 amps 4. Discuss installation questions here. The point is that they don't want a main breaker to be able to come off of the bus while still hot. I plan to install surface-mount switchable circuit breakers between each pv panel and controller to provide circuit protection and a circuit disconnect. The panel can then be backfed by up to 100A or so PV breaker. 10 (E) Backfed Circuit Breakers. Released for: Schneider Electric USA Apr 2, 2024 · Upgrades could include replacing the main breaker with one of a higher rating, adding a subpanel with a dedicated solar circuit, or installing an external disconnect switch for supply side connections to meet the requirements of NEC 705. I don't trust the (40A) stab-lok breaker in the Aug 7, 2017 · The transformerless inverter has ground fault protection built in. Except one twist. There are some situations where the circuit breaker would need replacing, but those are rare and generally involve replacing the circuit breaker with a higher The circuit breaker is technically called an Over Current Protection Device, or OCPD. I've also been testing those with my home-brew circuit breaker tester (current transformer and space heaters). Apr 16, 2019 · I'm swapping out a 100 amp panel that was damaged for another 100 amp panel. Dec 30, 2022 · Seems like feeding two inverters through a double poll breaker to then feed 15 amp breakers os doubling up on breakers, if an appliance failed on a 15 amp circuit wouldn't in turn protect everything upstream from there. Mar 9, 2017 · Heschen DC Molded Case Circuit Breaker MCCB, HSM1PV-250, 2 Poles, DC550V 200A, Photovoltaic Circuit Breaker, for Solar PV System Solar Panels Grid System 4. If the load is 60 amps or less you can feed the panel with a 60 amp breaker and backfeed a 60 amp breaker on the bus. ) 15 amp breaker has 10 panels 9 amps 3. 20) + (BUSBAR - MAIN OCPD) = MAX PV (A) Rule is the sum of the main breaker and solar breaker can't be over 125% of the panel rating. Looks like yours was at the very top. Mar 9, 2023 · How Do I Back Feed My Generator? Assuming you would like a step-by-step guide on how to back feed your generator: 1. 25 I would need Aug 12, 2015 · The breakers in a junction box protect the wires from each panel or sets of panels from being overloaded, in a case where one panel wiring shorts out and the other panels back feed to it. The cable lengths also can't be longer than 10 feet to adhere to the 10 ft tap rule in the NEC. However, you probably don't need 200A. Sep 29, 2020 · It might be difficult to provide a foolproof interlock for the backfed breaker though. If that is the case, then you could avoid getting a smaller main breaker. To use an interlock kit, you must first turn off the utility power source at the main circuit breaker in the electrical panel. This levels out the amperage distributed across the bus. OP should not have used a gfci breaker to back feed into the service panel. Jun 22, 2020 · Because fed from 200A at the top and 200A at the bottom, the current is opposite and cancels out. 25 X 45= 56. The sub-panel is in the same structure as the main panel, so the sub will rely on one of the breakers in the main panel as it's main breaker. The entire bus carries 120A, which overloads it. The circuit breakers I'm looking at appear to be polarity specific, with terminals marked "Bat/Line" and "Aux/Load. A breaker does not care which direction current flows. You can actually use a sub panel, if you put a higher rated sub panel in, put the main breaker in that, and feed the old box like a sub panel. Derating Your MSP for Solar Nov 29, 2024 · The plate prevents the circuit breakers for the utility power source and the generator power source from being turned on at the same time, ensuring that only one power source is connected to the electrical system at a time. Dec 20, 2022 · It sounds like you have a grid-tie solar system that uses vampire taps on the incoming service wires. The question is, most panel manufactures sell retaining clips that are designed only for the top locations on the buss. 12(D)(2)(3)(B)). For details about selecting circuit breaker, see the Inverter datasheet. See the compiled list below: Breakers that can be back fed and exceptions (This is a work in process list, and does not include legacy Jun 7, 2016 · The code requires a retaining clip for the solar back feed breaker that is placed in the bottom left/right position in the main breaker panel. And the most cost effective way to run your house in case the grid goes down, is a generator. 2. That's a pretty good solution. So you could have a 100A PV breaker if sum of loads is 100A. That way, you reduce the chances of electrical malfunctions. Note: More requirements are listed on NEC 690 through the NFPA free access page , and designers are encouraged to read further. Mar 30, 2023 · I'm sure in this case the expert was told you have an "all-in-one" with a center main breaker, and envisioned a panel choc-a-bloc full of branch circuit breakers, and gave correct advice for that circumstance not yours. Jan 5, 2024 · As you can tell in the video above, when people backfeed their homes, they will make a backfeed cord with 2-male plugs connected to the generator. That has been a problem because not all manufacturers have hold down hardware for all of their breakers and the solar companies think that batteries are exempt because the PV breaker is exempt. The sub may feed all the current loads, but there is nothing to stop someone in the future adding 3 125a breakers in the remaining spaces to outbuildings or plenum heaters or whatever that draws the full 200a from the utility plus your 50a solar. I'm waiting for the manufacturer to get back to me. 2 ratings. I can't find anything to suggest the circuit breaker needs to be 125% of the inverter output rating. 240 - 175 = 65 amps. Specifically 705. A breaker acceptable for reverse feed typically exhibits the following characteristics: Absence of "LINE" and "LOAD" markings on the top and bottom ends of the breaker. For people who have experience with solar panels and/or work in the industry. Aug 7, 2017 · The transformerless inverter has ground fault protection built in. Adding spaces w/ my new panel. Method 1: Backfeed breaker at end of busbar (120% Oct 2, 2024 · 2) The back feed breaker(s) must be at the oppisit end of the Busbar than the main breaker so no one part of the busbar sees all of the current For a 200A busbar in a breaker panel with a 200A main breaker, this is the math: Backfeed calculation (120% rule): 1. Apr 2, 2022 · All a back fed AC breaker is is a normal AC breaker where the load side is being used to feed the line side. 65amps so I need an 80amp breaker in the main panel to back feed correct? Assuming what I have said above is even correct, I still have the issue that I cannot get an 80amp breaker in either panel. DC circuit breakers play a crucial role in protecting solar panels against potential electrical faults and ensuring the smooth operation of the entire system. Dc circuit breakers for solar panels: Everything You Need to Know When it comes to solar power systems, safety is of utmost importance. Mounting the Switch: The transfer switch should be positioned near the main electrical panel for ease of connection. Recently, I discovered that the solar backfeed circuit breaker has caused damage to my main electric panel. 25 I Jan 17, 2024 · Turn off the primary circuit breaker to reduce the building’s power supply. In you scenario the "Barn" solar system would be like a generator hookup, the solar system would act as a generator to feed the house main panel which cannot/should not be done with the Grid breaker closed. Nov 15, 2023 · For functional purposes can I just run all my wires to the needed junction boxes, into the conduit, and then bring it to the back feed breakers? Click to expand Microinverter AC wiring is largely just like regular house wiring in rules. The reason why it isn't a 200% rule, is the heating among the branch breakers. , in summation. If the panel is rated at 100 amps and is fed by a 100 amp ocpd, the maximum rating of the solar inverter breaker would be 20 amps. Electricity enters the main breaker by the branch circuit breaker of the outlet. Each breaker in the upgraded system (sub panel) 1. Circuit breakers are to protect the wire and should be sized correctly. 68 kW AC output. 25 Max Backfeed source + 200A Nov 1, 2019 · I have a set of design questions. Plug-in type backfed circuit breakers connected to a stand-alone inverter output in either stand-alone or utility-interactive systems shall be secured in accordance with 408. North America 208L . 46 kW solar panel and microinverter system has been designed to interface with my 200 amp utility service. In this case, the Solar Edge 10000 single phase residential inverter has a continuous output rating of 42 amps. Circuit breakers that are marked “line” and “load” shall not be Jan 30, 2020 · This includes all Square D industrial thermal-magnetic and electronic trip circuit breakers. If the service panel was left supplied by the meter (utility) you still need to deal with the buss rating of the 100 amp buss being supplied by 40 amps (two 20 amp two pole) of solar Dec 20, 2021 · If the grid-tied solar inverter (GTI) is connected via another breaker, then, since there is no mechanism I know of which can interlock the main breaker with TWO branch-circuit breakers, it would be possible to have both the generator and the GTI connected to the load center simultaneously. The 100 amp & the service head, instead of being put on a breaker. Plug-in type back-fed circuit breakers connected to a stand-alone inverter output in either stand-alone or utility-interactive systems shall be secured in accordance with 408. com Marking requirements The circuit breaker is technically called an Over Current Protection Device, or OCPD. They have to be rated for a least 70 amps even if his back feed circuit breaker is only 50 amps. It should be relatively easy if you have ever replaced an end on an extension cord. Aug 26, 2022 · A circuit breaker is an easy fix. Both 200amp panels have 200amp main breakers thus leaving me only 40amps for the PV. In our case, the maximum back-fed breaker size would be 40 amps (240 - 200). This seems problematic. I am not kidding. See the compiled list below: Breakers that can be back fed and exceptions (This is a work in process list, and does not include legacy No problem. Oct 15, 2018 · For instancewhen you have a dual feed into a panel like utility power and a generator you need an interlock. The breaker protects the circuit downstream of it. Getting 8. The job should be straightforward. For example, a 200 Amp electrical panel is rated with a 200A busbar, and commonly has a 200A Main OCPD breaker. Mar 25, 2024 · To support PV, consider a 200A (or 225A) breaker panel with 100A main breaker (125 if allowed). Maximum continuous output Jul 16, 2020 · If AC breaker used for DC, the distance between contacts may not be enough to stop the arc. Specifically the let's say you are getting solar with a 70A breaker because the solar has an AC rating of 12kW and can feed 50A into the main panel. I'm not a fan, but okay. Ensure that your generator is properly grounded. So you can buy a bigger panel and keep your 200A breaker. An interlock is basically a special set of two pairs of linked circuit breakers that install into your existing circuit breaker panel: 3 Technical. 10 (E) (E) Back-fed Circuit Breakers. Mar 28, 2020 · I'm running off a critical loads subpanel with a 70a backfeed breaker. It must be adequately grounded and installed following local electrical codes and standards. ) It is theoretically possible to turn on a bunch of stuff in your house that would exceed the bus bar rating by 20%. Sep 25, 2020 · which was crammed with all sorts of stuff – two sets of different – 50amp 240v breakers feeding two spa panels, a 40 amp breaker feeding the A/C Unit , a 40 amp breaker feeding the microwave/oven combo, then a 125amp breaker feeding a MLO panel about 15ft on the other side of the wall in the garage. 2 x 200A = 125% Max back-feed source + 200A 240A = 1. Now that i have extra spaces for a breaker, do you think i should Jul 21, 2017 · However, this relates to DC circuits. The previous panel had the solar hot tapped in btwn. Most breakers also have a fast magnetic trip, activated around 5x rated current, e. In this article, we will delve into the world of DC circuit breakers for solar panels, exploring A circuit breaker can be used to disconnect the power of the UPS from the electrical circuit to avoid allowing electricity generated by the UPS to feed back into the power grid. Oct 16, 2009 · Be aware that battery systems such as the Tesla Power Wall are not exempt from hold down hardware for back-fed breakers. For the 120% rule to work, the load breakers must be between main and solar breaker. 1. There are several different ways this can be done per the NEC but the most common method for solar residential installs is by connecting it to the end of a busbar using the 120% rule (705. Likely your hybrid doesn't need 100A breaker. Factory sealed, with the Dec 29, 2023 · Say I connect a 100A source and a 20A source at one end of a 100A bus, and a 120A load at the other end of the bus. During periods of time with no solar or battery support, it means all those critical loads are limited to the 70a feed from the main panel, which could be a problem (especially if you want to charge the battery from the grid). This is especially important in facilities using multiple UPS systems, as backfeed from any one system could potentially disrupt the entire electrical network. 20) + (BUSBAR - MAIN OCPD) = MAX PV (A I'm assuming something like a farm panel with feed-through lugs and 8-spaces. However, it is important to note that residential breakers with arc fault (AF) and ground fault (GF) capabilities are NOT suitable for back feeding. Can’t I do this 1. The degree of backfeed is contingent upon the specific inverter linked to your solar setup. 25 to get the maximum continuous inverter AC output. (60 amps is a common breaker size). Article 690 requirements apply to solar PV systems. Back feeding can be dangerous if your generator is not properly grounded. An electric panel is backfed when the main breaker is mounted in the cluster of breakers on the branch bus, instead of being separate, vertical, and above or below the branch-circuit breakers. xqc vqzzm llweyqb qicns mutmq fnsx nfyfjo sbwn sjv aisczd plty fhbo ush quf kqn