The previous articles covered “what to buy”; this one covers “how to install it.” A 36-channel system is large enough for problems to arise during installation—you can spot an issue with 4 cameras at a glance, but with 36 cameras, all you will see is “a few black screens.” Read prices in real time.
I. Draw up a cable schedule before buying anything
The most common mistake with a 36-channel system is buying and installing as you go, then adding more equipment along the way. The correct order is:Create a cable schedule first, then place your order.
A cable schedule is a spreadsheet with one row for each point. At a minimum, it should include these seven columns:
| Field | What to enter | Why it matters |
|---|---|---|
| ID | CH01, CH02… | Corresponds to the NVR channel and App name |
| Location | Rear staircase on the third floor | Determines the cable route during installation |
| Purpose | Entrance/exit / checkout / shelving | Determines the resolution and whether 4K is required |
| Switch | SW-A port 3 | Determines which cable plugs in where |
| Cable length | Estimated meters | If it exceeds 80 meters, the route needs to be changed |
| Cable type | Cat6 outdoor / indoor | Determines the quantity to purchase |
| Notes | Requires conduit, requires surge protection | Materials to prepare before installation |
II. Cabling: Cat5e is sufficient, but Cat6 is recommended in two situations
PoE cameras do not require high-speed networking—one 4K main stream is approximately 8Mbps, while Cat5e’s 1Gbps is 125 times that. So the answer to “Is Cat5e sufficient?” is:Yes. However, Cat6 is recommended in these two situations:
- The cable run is close to 80–100 meters—Cat6 has thicker conductors (23AWG compared with Cat5e’s 24AWG), resulting in lower resistance and less voltage drop.
- It runs in the same cable tray as the power cables—Cat6 has tighter twists and better resistance to interference.
As for Cat6a / Cat7, they are over-specification for PoE cameras—their value lies in 10Gbps and higher bandwidth, which cameras do not use.
III. Distance: two limits, not one
Most people only know “100 meters for Ethernet cables,” but PoE has a stricter limit:Power delivery is recommended not to exceed 80 meters.
| Distance | Data transmission | PoE power |
|---|---|---|
| 0–80 meters | ✔ Normal | ✔ Normal, with plenty of headroom |
| 80–100 meters | ✔ Still works | ⚠ Significant voltage drop; high-power devices may restart |
| Over 100 meters | ✘ Not guaranteed | ✘ Not recommended |
Why is power delivery more demanding? Because voltage drop is proportional to current, and current suddenly increases when infrared lights and pan-tilt motors start up. Here is a simplified estimate (Cat6 24AWG copper cable, 802.3af/at two-pair power delivery):
Voltage drop = Current × Loop resistance × Cable length
100 meters, 0.25A (12W): approximately 2.1V drop (4.4%) → still usable
100 meters, 0.5A (24W): approximately 4.2V drop (8.8%) → close to the limit
(This is an estimate; actual results are affected by cable purity, temperature, and connector quality)
Practical conclusion:Keep the distance within 80 meters whenever possible.If it exceeds that, consider adding a switch midway (for nearby power delivery) instead of forcing the use of a longer cable.
IV. Outdoor cabling: three locations that will inevitably cause problems
1. Water entering the connectors (most common)
RJ45 connectors are the most vulnerable point in the entire system. When rainwater flows along the Ethernet cable to the connector, it can cause oxidation and poor contact. The symptom is “intermittent disconnections”—the connection does not fail completely, making the problem especially difficult to diagnose. Three solutions:
- Drip loop—Bend the cable downward into a U shape before it enters the connector, allowing water to drip off at the lowest point instead of flowing along the cable.
- Self-fusing tape + waterproof box—First wrap the outside of the connector with self-fusing tape, then place it in a waterproof connector box.
- Do not use ordinary electrical tape—Regular electrical tape will fail after a few months of exposure to sun and rain.
2. Cable jacket deterioration
Indoor cable (with a PVC jacket) will become hard and crack after prolonged exposure to sunlight, allowing water to enter. Outdoor sections must use outdoor-rated cable, or be fully enclosed in PVC conduit/cable trunking. Conduit also has another advantage: you can replace the cable later without pulling a new one.
3. Too few fixing points
If 36 cables are not secured every 3–5 meters, they will sway in the wind, creating stress at the connectors over time and eventually pulling them loose. Use stainless steel cable clips or nylon zip ties to secure them,do not press the cables down directly with iron nails(this can damage the cable cores).
V. Lightning protection and grounding: 4KV protects only one side
The Reolink 8-port switch (PS1) is rated for 4KV surge protection, but that protection is on theswitch endInduced lightning strikes or power-grid surges can travel through the Ethernet cable, while the camera end has no protection at all.
| Location | What is needed | Description |
|---|---|---|
| Switch end | 4KV surge protection (built into PS1) | Not listed in the official PS1E summary |
| Camera end | Ethernet cable surge protector | Recommended for long outdoor cable runs |
| Grounding | Connect to the building's grounding system | To be handled by a licensed electrician |
| Power | UPS or surge-protected power strip | See the next section |
VI. Rack and Cooling: 1U Is Not for Desktop Placement
The NVS36 is a 1U rack-mount unit (approximately 44.5 mm high), designed to be installed in a 19-inch rack or low-voltage cabinet. Three key points:
- Do not stack it with the switch—An 8-port switch generates noticeable heat when fully loaded; stacking it on top of the NVR is equivalent to applying heat from both sides.
- Leave ventilation space—Leave clearance at the front and rear of the rack. A sealed low-voltage cabinet must have ventilation openings or a fan.
- Hard drive vibration—Three hard drives operating simultaneously will generate vibration. Secure the rack properly and do not place it on a shaky shelf.
Hard drive temperature is critical to service life: surveillance-grade hard drives operating continuously above 50°C will have a significantly shorter lifespan. If the chassis feels hot to the touch, cooling is insufficient.
VII. UPS: The Cost of a 36-Channel Power Outage
During a power outage, the NVR, switch, and all 36 cameras will stop operating. To keep the system running, the UPS mustsimultaneouslysupply power to:
| Equipment | Quantity | Estimated power consumption |
|---|---|---|
| NVS36 (including 3 hard drives) | 1 | Approximately 40–60W |
| 8-port PoE switch | 5 | Approximately 100–120W per unit at full load |
| Total | — | Approximately 540–660W |
VIII. Seven Steps for Installation
1. Mark the locations—First mark all 36 locations and their heights on the floor plan, then verify the viewing angles on site (do not rely solely on the drawings).
2. Complete the cable schedule—Record the cable length, cable type, switch, and notes for each location.
3. Run the cables—Run the cables before installing the equipment. After the cables are laid but before the connectors are attached, continuity testing must be performed.
4. Terminate the connectors—Crimp according to the T568B standard, then test each cable individually.
5. Installation——Before installation, first confirm that the cable has passed testing. Do not “install it only to discover that the cable is faulty.”
6. Power-On Test——Power on each switch one by one and confirm that the PoE indicator on each unit lights up.
7. Recording Verification——Confirm that all 36 channels have video, recording, and synchronized time.
9. Acceptance: Five Checks That Must Be Completed
| Item | How to Test | Pass Criteria |
|---|---|---|
| Cable continuity | Test all 8 cores one by one with a cable tester | All 8 cores are connected, with no short circuits |
| PoE power supply | Check the switch port indicators | The power indicator on every port is lit |
| Video | Check each channel on the NVR | All 36 channels display video |
| Recording | Replay the most recent 1 hour | Every channel has continuous footage |
| Time | Compare with the time on a mobile phone | Difference is within 1 minute |
The fifth check is the one most often overlooked. If the times on all 36 cameras are not synchronized, searching for “11:00 p.m. last night” may take you to the wrong footage—which can be fatal when presenting evidence.Be sure to enable NTP time synchronization after installation.
10. Ten Most Common Failure Points
| Symptom | Most Likely Cause | How to Check |
|---|---|---|
| One camera has no video at all | Cable not properly crimped / port not supplying power | Test that cable with a cable tester |
| Repeated restarts after nightfall | Insufficient power / aging power supply | Check PoE power consumption and voltage |
| Intermittent disconnections | Connector water ingress and oxidation | Open the connector and check for oxidation |
| Video stuttering | Insufficient bandwidth or cable interference | Check whether it shares a conduit with the power cable |
| Several cameras fail simultaneously | Switch failure or power outage | Check that switch |
| Recordings have gaps of a fixed duration | Hard drive or card write issue | Check hard drive health |
| All times are different | NTP not enabled | Set up time synchronization |
| PTZ camera stops midway through rotation | Insufficient power supply (12W at the limit) | Switch to 802.3af or higher |
| Not visible in the app but visible on the LAN | Uplink not connected to the router | Check the uplink port |
| Ripple patterns on the video | Power interference / grounding issue | Check the grounding and cables |
11. Equipment Comparison
| Item | Model | Price | Notes |
|---|---|---|---|
| 36-channel NVR | Reolink NVS36 / RLN36 | HK$1,899 | 4 GbE camera ports, no PoE |
| 8-port PoE+ switch | Reolink RLA-PS1（120W） | HK$599 | Supports 8 cameras per unit; 5 units are needed for 36 cameras |
| Cat6 cable | — | Local electrical supply store | Not in stock in-store |
| Ethernet surge protector | — | Local electrical supply store | Recommended for long outdoor cable runs |
12. Frequently Asked Questions
How many metres of network cable are needed for 36 cameras?
Estimate each cable run based on the distance to its location, then add 15% for wastage. Assuming an average of 30 metres, 36 runs require approximately 1,080 metres, or about 4 boxes（305 metres per box）. The actual quantity should be calculated based on the cable schedule.
Can Cat5e be used?
Yes. Cameras only require around 8Mbps, while Cat5e supports 1Gbps, which is far more than needed. However, if the cable run is close to 80 metres or shares a conduit with power cables, Cat6 is recommended.
Can the cable share the same conduit as the power cable?
Technically, yes, but there is a risk of interference. If they must share the same conduit, use shielded cable and maintain adequate separation, or install a separate divider.
What should I do if the cable run exceeds 100 metres?
Add a switch midway for local power delivery and data transmission instead of forcing an excessively long cable run. Alternatively, use fibre optic cable with media converters（at a higher cost）.
Are waterproof connectors required?
They are essential outdoors. Standard connectors are sufficient in dry indoor locations, but a drip loop is still recommended.
How many days of footage can be stored for 36 cameras?
Approximately 31 days at 2K and 15 days at 4K（48TB maximum）. See the article on practical NVS36 configuration for details.
Can I install it myself?
The equipment can be installed yourself, but the power supply and grounding must be handled by a licensed electrician. For a 36-channel system, it is recommended to hire an installation team with CCTV experience.
How to check if you find several disconnected lines after installation?
First check the switch port indicator lights, then use a cable tester to test the cable, and finally remove the connectors to check for oxidation. Troubleshoot each item according to the table in Section 10.
13. Further Reading
- NVS36 36-Channel Practical Configuration——Three Architectures and Actual Hard Drive Calculations
- How to Choose a PoE Switch——65W vs 120W
- Three Formulas for Power Supply, Bandwidth, and Hard Drives
- Complete CCTV Series Guide——Starting with the Number of Cameras