7.5 HP Electric Driven Dewatering Solution
When water is standing where it shouldn't be — in a basement, a construction pit, a factory sump, or an outdoor drainage channel — you need a pump you can lower into the water and trust to keep running. That's exactly what the Hydroman® TBZ35.5 is built for. It's a 5.5 kW / 7.5 HP electric-driven submersible sump pump, engineered in cast iron for the kind of demanding, unglamorous drainage work that industrial sites, contractors, and facility managers deal with every day.
This page walks you through what the TBZ35.5 is, how it performs, where it fits into your operation, and how to make sure you're specifying the right configuration before you place an order.
You'll find the TBZ35.5 doing its job fully submerged at the bottom of a sump, pit, tank, or excavation — pulling in dirty water, drainage water, wastewater, or general nuisance water and moving it out of your way. It's a vertical submersible pump, meaning the motor and pump end are built as one sealed unit that goes straight down into the water column, without the need for a separate dry-installed motor or a shaft-driven arrangement.
Because it's built around a cast iron pump casing and impeller housing, the TBZ35.5 holds up in the kind of industrial submersible sump pump applications where abrasive particles, occasional debris, and continuous duty cycles would wear out a lighter-duty pump quickly. Whether you're running it in a construction dewatering pit, a plant sump, or a basement sump pit, the same core design carries over — you're getting a pump built for mechanical durability first, with performance tuned around real drainage flow rates rather than marketing numbers.
If you're comparing this against a typical residential submersible pump, the difference shows up mainly in continuous-duty motor construction, cast iron wear surfaces, and a control setup that can be scaled to fit fixed industrial installations — not just a plug-and-drop consumer unit.
What Makes the TBZ35.5 a Practical Choice
The 5.5 kW / 7.5 horsepower sump pump motor at the heart of the TBZ35.5 is sized for jobs that go beyond what a fractional-horsepower sump pump can handle. If you're dealing with high inflow rates — a construction excavation that keeps filling with groundwater, or an industrial sump that sees continuous process water — this is the power class where an electric sump pump stops being a stopgap measure and starts being your primary dewatering equipment.
The TBZ35.5 is a cast iron submersible sump pump through its wetted components — casing and impeller housing — which is the material choice you want when the water you're pumping isn't clean. Cast iron resists the abrasion and mechanical wear that comes from suspended solids, small debris, and the general roughness of drainage water far better than plastic or thin-gauge stainless sheet metal would in the same duty cycle. For sites where corrosion resistance to specific chemical exposure matters more than abrasion resistance, ask your Hydroman® contact about whether a stainless steel submersible sump pump variant is appropriate for your water chemistry — material selection should always match your actual fluid, not a general assumption.
Because the TBZ35.5 is a vertical submersible pump, you lower the entire unit into the sump or pit and it operates fully submerged — there's no separate dry-installed motor room, no long drive shaft, and no additional civil work to house the drive train. That single design choice is what makes a submerged sump pump like this one so much faster to install and reposition compared to a dry-pit or self-priming surface pump doing the same job.
This is a submersible dirty water pump in the true sense — it's engineered around drainage water, wastewater, sump water, construction site runoff, and general industrial process water, not filtered or potable water. That said, "dirty water" doesn't mean "anything goes": the TBZ35.5 is matched to a specific maximum solid passage size (see the specification table above), and it isn't intended as a heavy-duty sludge or slurry pump unless your particular model and impeller selection are confirmed for that duty. If your site regularly produces water with large solids, stringy debris, or high sludge content, talk to Hydroman® about impeller and solids-handling options before you order.
For fixed installations, the submersible sump pump with optional control cabinet configuration takes a lot of the guesswork out of day-to-day operation. The control cabinet handles motor protection, start/stop control, and can be configured to your site's control philosophy — whether that's manual switching, float-switch automation, or integration into a broader plant control system. It's a worthwhile add-on any time the pump is going into a permanent installation rather than a temporary or rental deployment.
Hydroman TBZ35.5 Submersible Sump Pump Curve
TBZ35.5 Technical Specifications
Here's the core data sheet information you'll want on hand before speccing this pump for your site. Where a figure depends on your specific discharge configuration or voltage, we've noted the typical range you should expect for a 5.5 kW class submersible sump pump in this duty category, and we recommend confirming the exact curve for your unit against the current Hydroman® datasheet before finalizing an order.
| Item | TBZ35.5 |
| Pump Type | Submersible Sump Pump |
| Drive Type | Electric, direct-coupled submersible motor |
| Motor Power | 5.5 kW / 7.5 HP |
| Pump Structure | Vertical Submersible |
| Application | Sump drainage, dewatering, dirty water transfer |
| Installation | Fully submerged |
| Main Material | Cast Iron (pump casing, impeller housing) |
| Discharge Outlet | DN80 (3"), model dependent |
| Flow Rate | Up to approx. 75 m³/h (330 US GPM), duty-point dependent |
| Total Head | Up to approx. 34 m, duty-point dependent |
| Maximum Solid Passage | Approx. 8.5 mm, depending on impeller selection |
| Protection Class | IP68 submersible rating |
| Insulation Class | Class F or higher |
| Cable Length | Standard 10 m submersible cable (extended lengths available on request) |
| Control | Optional control cabinet |
| Duty | Suitable for continuous and intermittent operation, subject to ambient water temperature |
A quick note on how to read this table: motor power tells you how much work the pump can do, but flow rate and head are what actually determine whether the pump matches your site. A 7.5 horsepower sump pump moving water 5 meters vertically will move noticeably more volume per hour than the same pump pushing water 20 meters up and out — so always size against your actual head and flow requirement, not motor power alone.
You don't need a single "ideal" application to justify this pump — its combination of motor power, cast iron construction, and submersible design covers a fairly wide range of drainage scenarios. Here's how it typically breaks down by site type.
Basement and below-grade drainage. If you manage a building with a basement, underground parking structure, or any below-grade space prone to water intrusion, a submersible pump for basement use needs to handle intermittent high-inflow events — heavy rain, groundwater seepage, or plumbing failures — without hesitation. The TBZ35.5's flow capacity gives it real headroom over lighter residential units when a basement is large or prone to significant inflow, which is part of why it gets specified as a best submersible sump pump for basement applications in commercial and multi-unit residential buildings rather than single-family homes with modest sump pits.
Industrial sumps and process pits. In manufacturing plants, treatment facilities, and processing sites, sumps collect everything from cooling water to washdown water to general process overflow. An industrial submersible sump pump in this class is expected to run for extended periods without babysitting, and the TBZ35.5's continuous-duty motor and cast iron wear parts are built with that expectation in mind.
Construction site dewatering. Excavations and foundation pits fill with groundwater and surface runoff constantly during a build. Contractors use pumps like the TBZ35.5 to keep pits workable, moving water fast enough that it doesn't hold up the schedule.
Outdoor drainage. With an IP68 submersible rating, the TBZ35.5 is suited to outdoor submersible sump pump duty — ponds, drainage ditches, low-lying yard areas, and temporary flood response — where the pump has to tolerate full submersion and outdoor exposure, not just splash resistance.
Pool and tank drainage. For draining swimming pools, above-ground tanks, or large containment basins, a submersible sump pump for pool use needs enough flow to empty a large volume in a reasonable timeframe. The TBZ35.5's flow rate range makes it a practical option compared to smaller consumer-grade pool pumps, particularly for commercial pools or large tanks.
High-temperature process water. If your drainage water runs warmer than typical ambient conditions — certain industrial cooling or process applications — you'll want to confirm the thermal rating of the specific motor and seal configuration before deployment. A high temperature submersible sump pump variant, where offered, uses upgraded seal and insulation materials rated for elevated fluid temperatures; standard configurations should not be assumed suitable for hot water service without that confirmation.
How a Submersible Sump Pump Like the TBZ35.5 Actually Works
It helps to understand the mechanics, especially if you're troubleshooting performance or explaining the system to a site team.
The pump sits at the lowest point of the sump or pit, fully submerged in the water it needs to remove. When the motor starts, it drives the impeller at operating speed inside the pump casing. Water enters through the intake at the base of the pump, gets caught by the spinning impeller vanes, and is accelerated outward through centrifugal force. That kinetic energy converts into pressure as the water is forced into the volute casing and pushed up through the discharge outlet, through your discharge piping, and out to wherever you're routing it — a storm drain, a holding tank, or an open discharge point.
Because the entire assembly is submerged, there's no priming step required the way there is with a surface-mounted centrifugal pump — as long as the pump is covered by water, it's ready to run. For sites that need the pump to start and stop automatically based on water level, that's where the optional control cabinet and a float switch come in: the float switch signals the control cabinet when water reaches a set level, and the cabinet handles the motor start/stop sequence without anyone standing at the pit.
Installing the TBZ35.5
Getting the installation right the first time saves you a service call later. A few things worth checking before the pump goes into the water:
Confirm your sump or pit dimensions give the pump adequate clearance on all sides and enough water depth for full submersion during normal operating levels — running a submersible pump with the top of the casing exposed, even briefly, isn't good practice for motor cooling. Match your discharge pipe size to the pump's actual outlet diameter, and keep the pipe run as direct as practical; every unnecessary elbow and length of pipe adds friction loss that eats into your effective head and flow rate. Verify your power supply — voltage, phase, and available electrical capacity — is compatible with the motor's rated draw before you connect anything, and route the power cable so it isn't pinched, kinked, or resting on sharp pit edges.
If you're using the optional control cabinet, have it wired and tested by a qualified electrician according to your local electrical code before the pump is put into continuous service. And once everything's connected, fully submerge the pump according to the installation manual before starting it — this pump is not designed to run dry, even briefly, and dry-running is one of the most common causes of premature seal and motor failure in any submersible pump.
Configurations and Options
The standard TBZ35.5 configuration gets you the cast iron pump, submersible motor, and standard-length power cable ready for manual operation. From there, most customers add one or more of the following based on how the pump will actually be used on site: the optional electric control cabinet for automated or protected operation, a float switch for level-based start/stop control, extended discharge fittings or piping matched to your layout, and an extended power cable length where the pump sits farther from the electrical supply than the standard cable allows.
Float switch compatibility, high-temperature seal upgrades, and stainless steel wetted-part construction are all configuration-specific — they're available, but should be confirmed against the exact TBZ35.5 build you're ordering rather than assumed as standard equipment. This is a case where a five-minute conversation with Hydroman® before ordering saves you a mismatched pump later.
Where the TBZ35.5 Fits Across Your Operation
Put simply: the Hydroman® TBZ35.5 is built for industrial and commercial drainage work where water needs to come out of a sump, pit, basement, tank, or excavation reliably and without constant supervision. Its electric-driven, cast iron, vertical submersible construction is what lets the same pump move between a factory floor, a construction site, a below-grade parking structure, and an outdoor drainage application without needing a different piece of equipment for each one.
TBZ35.5 Compared Against Other Sump Pump Configurations
There isn't a single "best submersible sump pump" that fits every job — the right pump depends on your flow, head, water quality, and installation type. What the table below does is show you where the TBZ35.5 sits relative to other common sump pump categories, so you can judge fit against your own requirements rather than a generic ranking.
| Pump Category | Typical Application | TBZ35.5 Fit |
| Submersible Sump Pump | General sump and drainage duty | Yes — core application |
| Electric Driven Sump Pump | Fixed-site electrical installations | Yes |
| Submersible Dirty Water Pump | Drainage water with suspended solids | Yes, within rated solid passage |
| Vertical Submersible Sump Pump | Direct submerged installation, no dry pit | Yes |
| Cast Iron Submersible Sump Pump | Abrasive or industrial-grade water | Yes |
| Stainless Steel Submersible Sump Pump | Corrosive or chemically aggressive water | Available as a separate material configuration — confirm with Hydroman® |
| Pump with Optional Control Cabinet | Automated or unattended fixed operation | Yes, as an add-on |
The decision to specify this pump usually comes down to a few practical factors rather than any single headline feature.
Industrial-grade construction means the pump is built to handle continuous or near-continuous duty cycles, not occasional light use. The 7.5 HP electric drive gives you enough flow and head capacity to handle sites where a smaller pump would be constantly cycling or simply undersized. Cast iron construction holds up against the abrasive, unfiltered nature of real drainage water instead of wearing out after a season. The optional control cabinet lets you scale from a manually operated unit to a fully automated fixed installation without switching pump models. And because Hydroman® works with customers on flow rate, head, water quality, solids content, power supply, and installation conditions before finalizing a configuration, you're not guessing whether the pump you order will actually match your site.
 |
Item No. | Part name | Material | Item No. | Part name | Material | |
| 01 | Hose coupling | Cast iron | 28 | Rotor | Shaft: AISI420SS | ||
| 02 | Handle | Rubber & steel | 31a | Bearing | Ball bearing | ||
| 05 | Upper cover | Cast iron | 31b | Bearing | Ball bearing | ||
| 11 | Motor body | Cast iron | 33 | Motor protector | — | ||
| 13 | Pump body | Cast iron | 34 | Mechanical seal | Sic-Sic/Carbon-Sic (≤2.2kW) Sic-Sic/Sic-Sic (≥3.7kW) |
||
| 14 | Impeller | High chrome alloy | 35 | Oil seal | — | ||
| 16 | Inlet plate | Ductile iron | 47 | Cable | — | ||
| 25 | Strainer | Steel | |||||
| 27 | Stator | — |
Before you place an order, it's worth working through the same questions Hydroman®'s technical team will ask you.
Getting these six answers right before you order is the single biggest factor in whether a submersible sump pump performs the way you expect once it's installed.
A little routine attention keeps this pump running for years instead of seasons.
1. Inspect the pump body, power cable, cable connections, and discharge piping on a regular schedule, and don't wait for a failure to notice a worn or damaged cable jacket.
2. Keep the pump intake clear of debris, sediment buildup, and anything that could restrict flow into the impeller.
3. Check motor insulation, cable condition, and any control cabinet components periodically, particularly in installations exposed to moisture or temperature extremes.
4. Inspect wear components like the impeller and wear ring based on your actual duty cycle — a pump running continuously in abrasive water needs more frequent inspection than one used intermittently in cleaner conditions.
5. And after any application involving heavy sediment, sludge, or contaminated water, clean the pump according to the manufacturer's guidance rather than leaving residue to harden on internal surfaces.
What is a submersible sump pump? A submersible sump pump is a pump designed to operate fully submerged in water, typically installed at the bottom of a sump, pit, or tank. Unlike a surface pump that draws water up through suction, a submersible unit sits in the water itself and pushes it out through a discharge line, which eliminates priming issues and generally runs quieter since the motor noise is dampened by the surrounding water.
Is the TBZ35.5 suitable for basement drainage? It can be, depending on your basement's actual inflow rate and the depth of your sump pit. For a large commercial basement or a space with significant groundwater intrusion, the TBZ35.5's flow and head capacity are well matched. For a small residential sump pit with modest, occasional inflow, a smaller pump is likely more appropriate — this is exactly the kind of decision worth confirming against your flow and head numbers rather than assuming based on the name alone.
Is the TBZ35.5 an electric sump pump? Yes. It's a fully electric-driven submersible sump pump, with the motor integrated into the submersible unit itself — there's no separate diesel or hydraulic drive involved.
What horsepower is the TBZ35.5 sump pump? It's rated at 5.5 kW, equivalent to 7.5 HP.
Can the TBZ35.5 handle dirty water? Yes, within its rated maximum solid passage size. It's built as a submersible dirty water pump for drainage water, wastewater, and general sump water, but it isn't intended for water with oversized solids, heavy sludge, or fibrous debris unless a specific configuration for that duty has been confirmed.
Is a control cabinet available? Yes, as an optional add-on. The control cabinet handles motor protection and start/stop control and is a practical addition for any fixed, permanent installation.
Can the TBZ35.5 be used outdoors? Yes — with its IP68 submersible protection rating, it's suited to outdoor drainage applications. As with any outdoor electrical installation, make sure your power connections and control equipment are also rated and protected appropriately for outdoor exposure.
Can I use a float switch with the TBZ35.5? Float switch compatibility depends on your specific pump and control configuration — confirm this with Hydroman® at the time of order so the float switch and control cabinet are matched correctly to your installation.
How do I choose the right sump pump? Start with your required flow rate and head, then confirm your water quality, expected solids size, available power supply, and installation conditions. Sharing these details with Hydroman® is the fastest way to land on the right configuration the first time.
Request a Quote for the Hydroman® TBZ35.5
If you're ready to move forward, or you're still narrowing down whether this is the right pump for your site, get in touch with your required flow rate, pumping head, water or medium type, expected solids content, available power supply, discharge pipe size, and the application location. Hydroman®'s team will work with you on pump specifications, configuration recommendations, and a formal quotation for the TBZ35.5 — or point you toward a better-matched model if your site's requirements call for it.
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